Avoid WiFi channel 12-13-14 when working with ESP devices

Recently we are experimenting with Home Assistant installed on A20-OLinuXino-LIME2 Home server and attaching different nodes made with our ESP8266/ESP32 boards and noticed odd behaviour os ESP when WIFI router is set on the higher frequencies channels.

Most of WiFi router default settings are with channel Auto selection, this means the router will try first Channel 1 if too much noise and drop packets due to overwhelmed with WiFi devices area will change it up and so on, so our developers decided that it’s smart idea to use the WiFi router on the highest possible channel. This will guarantee that this channel will be most noise and interference free from other WiFi devices. So our router was set to WiFi channel 13:

We use the ESP standard firmware and ESPhome code. This is what happens: When the code is flashed for first time, it experience some errors while connecting but manage to connect to the router.

Access Point: TP Link
Hardware Version: Archer C1200 v2.0
Firmware Version: 2.0.0 Build 20170206 rel.46023 (EU)

SUCCESS CH13 (first attempt after flashing the code)
============================

[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -40 dB
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Association Expired'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:479]: Event: Disconnected ssid='OlimexTenda' reason='Probe Request Unsuccessful'
[W][wifi:533]: Error while connecting to network.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -52 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Association Leave'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[I][wifi:502]: WiFi Connected!
[C][wifi:350]:   Local MAC: 18:FE:34:9C:61:DE
[C][wifi:351]:   SSID: 'OlimexTenda'
[C][wifi:352]:   IP Address: 192.168.0.203
[C][wifi:354]:   BSSID: B0:4E:26:6E:B2:73
[C][wifi:355]:   Hostname: 'esp8266-evb-pir-9c61de'
[C][wifi:357]:   Signal strength: -56 dB 
[C][wifi:361]:   Channel: 13
[C][wifi:362]:   Subnet: 255.255.255.0
[C][wifi:363]:   Gateway: 192.168.0.1
[C][wifi:364]:   DNS1: 192.168.0.1
[C][wifi:365]:   DNS2: 0.0.0.0
[D][wifi:511]: Disabling AP...

As you can see from the above the ESP try to connect twice but gets error: ‘Association Expired’ and ‘Probe Request Unsuccessful’ but on the third attempt it connects.

The problem comes later if for some reason ESP lose power and start again. This could easily happen if the ESP is powered by the mains and there is power blackout and power restore.

FAILURE CH13 (after cold restart)
=================================
[C][wifi:037]: Setting up WiFi...
[D][wifi:046]: Loaded saved wifi settings: OlimexTenda
[D][wifi:370]: Starting scan...
[D][binary_sensor:036]: 'PIR Sensor': Sending state OFF
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -55 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[W][wifi:568]: Restarting WiFi adapter...
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[W][wifi:568]: Restarting WiFi adapter...
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -54 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[W][wifi:568]: Restarting WiFi adapter...
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[W][wifi:568]: Restarting WiFi adapter...
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -52 dB
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[W][wifi:568]: Restarting WiFi adapter...
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[I][wifi:135]: Starting fallback AP!
[C][wifi:198]: Setting up AP...
[C][wifi:200]:   AP SSID: 'esp8266-evb-pir-9c61de'
[C][wifi:201]:   AP Password: ''
[C][wifi:210]:   IP Address: 192.168.4.1
[W][wifi:527]: Timeout while connecting to WiFi.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -57 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Association Leave'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi:527]: Timeout while connecting to WiFi.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -56 dB
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Association Leave'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:479]: Event: Disconnected ssid='OlimexTenda' reason='Probe Request Unsuccessful'
[W][wifi:533]: Error while connecting to network.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -51 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[W][wifi:439]: No matching network found!
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -54 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -53 dB
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'ESP_CA17E1' (8C:4B:14:CA:17:E1) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -54 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -53 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[W][wifi_esp8266:213]: wifi_apply_hostname_(esp8266-evb-pir-9c61de): lwIP error -16 on interface st (index 0)
[W][wifi_esp8266:483]: Event: Disconnected ssid='OlimexTenda' bssid=B0:4E:26:6E:B2:73 reason='Auth Expired'
[W][wifi:533]: Error while connecting to network.
[D][wifi:370]: Starting scan...
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 13
[D][wifi:431]:     RSSI: -53 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 

As seen from the log above, after power cycling ESP can’t connect to WiFi router anymore, most of the errors shown are ‘Auth Expired’

If we change the WiFi router settings to Channel 1-11:

All problems now are gone and ESP connects every time no matter how many time power is cycled.

SUCCESS CH11 (after cold restart)
=================================
[D][wifi:046]: Loaded saved wifi settings: OlimexTenda
[D][wifi:370]: Starting scan...
[D][binary_sensor:036]: 'PIR Sensor': Sending state OFF
[D][wifi:385]: Found networks:
[I][wifi:429]: - 'OlimexTenda' (B0:4E:26:6E:B2:73) 
[D][wifi:430]:     Channel: 11
[D][wifi:431]:     RSSI: -54 dB
[D][wifi:434]: - 'Haxor' (B0:48:7A:CE:8D:BC) 
[D][wifi:434]: - 'OlimexGuests' (C8:3A:35:4B:10:78) 
[D][wifi:434]: - 'OlimexAP' (00:1F:1F:11:7B:B3) 
[D][wifi:434]: - 'OlimexTest' (78:32:1B:90:D7:38) 
[D][wifi:434]: - 'ubnt' (00:27:22:7C:3C:70) 
[I][wifi:245]: WiFi Connecting to 'OlimexTenda'...
[I][wifi:502]: WiFi Connected!
[C][wifi:350]:   Local MAC: 18:FE:34:9C:61:DE
[C][wifi:351]:   SSID: 'OlimexTenda'
[C][wifi:352]:   IP Address: 192.168.0.203
[C][wifi:354]:   BSSID: B0:4E:26:6E:B2:73
[C][wifi:355]:   Hostname: 'esp8266-evb-pir-9c61de'
[C][wifi:357]:   Signal strength: -55 dB 
[C][wifi:361]:   Channel: 11
[C][wifi:362]:   Subnet: 255.255.255.0
[C][wifi:363]:   Gateway: 192.168.0.1
[C][wifi:364]:   DNS1: 192.168.0.1
[C][wifi:365]:   DNS2: 0.0.0.0
[D][wifi:511]: Disabling AP...
[C][ota:082]: Over-The-Air Updates:
[C][ota:083]:   Address: esp8266-evb-pir.local:8266
[C][api:025]: Setting up Home Assistant API server...
[I][app:060]: setup() finished successfully!
[I][app:099]: ESPHome version 2021.11.4 compiled on Dec  9 2021, 11:08:14
[I][app:101]: Project olimex.esphome-esp8266-evb-pir version 1.0
[C][wifi:488]: WiFi:
[C][wifi:350]:   Local MAC: 18:FE:34:9C:61:DE
[C][wifi:351]:   SSID: 'OlimexTenda'
[C][wifi:352]:   IP Address: 192.168.0.203
[C][wifi:354]:   BSSID: B0:4E:26:6E:B2:73
[C][wifi:355]:   Hostname: 'esp8266-evb-pir-9c61de'
[C][wifi:357]:   Signal strength: -55 dB 
[C][wifi:361]:   Channel: 11
[C][wifi:362]:   Subnet: 255.255.255.0
[C][wifi:363]:   Gateway: 192.168.0.1
[C][wifi:364]:   DNS1: 192.168.0.1
[C][wifi:365]:   DNS2: 0.0.0.0
[C][logger:233]: Logger:
[C][logger:234]:   Level: DEBUG
[C][logger:235]:   Log Baud Rate: 115200
[C][logger:236]:   Hardware UART: UART0
[C][gpio.binary_sensor:015]: GPIO Binary Sensor 'PIR Sensor'
[C][gpio.binary_sensor:015]:   Device Class: 'motion'
[C][gpio.binary_sensor:016]:   Pin: GPIO16
[C][captive_portal:151]: Captive Portal:
[C][ota:082]: Over-The-Air Updates:
[C][ota:083]:   Address: esp8266-evb-pir.local:8266
[C][api:134]: API Server:
[C][api:135]:   Address: esp8266-evb-pir.local:6053
[C][api:139]:   Using noise encryption: NO
[C][mdns:084]: mDNS:
[C][mdns:085]:   Hostname: esp8266-evb-pir-9c61de

Our blind guess is that ESP can’t connect reliable on the higher frequency channels. As far as you choose channels 1-11 everything is fine. We think that most people even do not notice this kind of erros if they routers are set to Auto channels as the chances to go up to 12-13-14 are very slim.

ESP32-POE and ESP32-POE-ISO back in stock

Silicon Labs stopped selling Si3204 POE controllers which were inside our very popular ESP32-POE and ESP32-POE-ISO boards. There is no stock anywhere neither information when they will be back in stock. So back in August we start searching for alternative and we evaluated several other solutions. We liked most Texas Instruments and made some prototypes and verified that they works fine.

Then we run blank PCBs in production but unfortunately we hit two major Chinese Holidays, so instead the blank PCBs to arrive in the normal 2 weeks we had to wait 5 weeks to produce our order then another week to arrive here.

Meantime we sold out all our stock of ESP32-POE and POE-ISO and created solid backlog before we stop the sales on the web.

We are glad that this week we shipped all backlog orders and now the boards are again for sale!

The new revisions of the boards are REV.G and the PCB info will be updated on GitHub tomorrow. From user point of view nothing changes – the new revision operates exactly the same and have same functionality as the previous Silicon Labs based solution.

STMP157-OLinuXino-LIME2 Open Source Hardware Industrial Grade Linux computer is in mass production with 4 variants

STMP157-OLinuXino-LIME2 Open Source Hardware Linux computer running Mainline Linux is in mass production in four variants:

• Industrial grade -40+85C (STMP157-OLinuXino-LIME2-IND) version running on 650 Mhz
• Industrial grade -40+85C (STMP157-OLinuXino-LIME2H-IND) version running on 650 Mhz with HDMI output (when HDMI works operating temperature is commercial as HDMI convertor is not industrial grade)
• Extended temperature -20+85C (STMP157-OLinuXino-LIME2-EXT) version running on 800 Mhz
• Extended temperature -20+85C (STMP157-OLinuXino-LIME2H-EXT) version running on 800 Mhz with HDMI output (when HDMI works operating temperature is commercial as HDMI convertor is not industrial grade)

User Manual for the boards is available on the product web page.

Debian and Ubuntu Linux images are pre-build and ready to install and run.

The images are build with Olimex script Olimage which is available on GitHub.

Olimage user manual explains what is included in it and how you can modify uboot and kernel to include drivers for devices which are not included in Olimex official images.

New iMX8QuadPlus System on Module is ready for prototyping

iMX8Quad Max board we developed is still waiting for components to verify the first prototypes, but we decided to develop one more SOC from iMX8 Plus series which we thought is filling niche where we do not have product.

This is how iMX8MPLUS-SOM was designed:

• MIMX8ML8DVNLZAB – Quad Core Arm Cortex-A53 running at 1.8Ghz with Arm Cortex-M7 co-processor running at 800Mhz and 2.3 TOPS Neural Processing Unit.
• 6GB LPDDR4 RAM
• Power management
• configuration EEPROM
• status LED
• LCD LVDS connector compatible with LCD-OLinuXino displays
• MIPI DSI connector
• 2x MIPI CSI comera connectors with Raspberry Pi compatible pinout
• 220 signals on 6 0.05″ step connectors with essential peripherials like:
  • PCIe-3.0
  • 2x CAN FD
  • HDMI 2.0a
  • SPDIF
  • SAI
  • 2x USB 3.0
  • 2x Gigabit Ethernet one of them with TSN
  • eMMC 5.1
  • SDIO 3.0 200Mhz
  • 4 UART
  • 6 I2C
  • 3 SPI
  • JTAG

MIMX8ML8DVNLZAB operating temperature is -40+105C which makes it perfect for both industrial and automotive applications.

Evaluation board iMX8MPlus-SOM-EVB is now designed with Dual Ethernet, Dual USB 3.0, PCIe, HDMI.

NXP is going to provide mainline Linux support for this SOC.

It’s impossible to comment any pricing at the moment, but it will be very competitive compared with similar industrial grade products.

Open Fest 2021 is back! Free your agenda for 14 and 15 of August when the biggest open source event in Bulgaria will take place in Sofia.

It’s good to see that slowly things come back to normal!

Open fest 2021 will be provided in normal face to face format in the open space – the King Boris garden – “Maimunarnika” where up to 1200 people can be hosted.

As always the participation is free of charge.

There will be the traditional soldering party with the help of the Open Fest 2021 volunteers from the Technical University club of Robotics.

Olimex is donating 50 pcs of our new Musical badge kits, which contain only PTH components and are very easy to solder even for beginners:

Musical badge is board with two sensor buttons which start and stop music play when touched.

The Open Fest dates are during our Summer Break so we are not be physically present there but will watch online the event.

Low Cost Open Source Hardware LoRa modules based on SX1276 are now in stock!

Open Source Hardware LoRa modules in two versions now are available for sale on our webshop:

868 Mhz is the free band for LoRa in Europe and we have six basic modules for this frequency.

LoRa868 is breadboard friendly and can be soldered directly on PCB or to be used on breadboard with headers.

LoRa868-ANT which includes +2dBi PCB antenna:

Created with GIMP

and LoRa868-EANT which includes +3dBi antenna for external panel mounting:

Created with GIMP

MOD-LoRa868 has UEXT plug connector and can be easily attached to any of our boards with UEXT connectors.

MOD-LoRa868-ANT and MOD-LoRa868-EANT variants are also available.

For North America 915Mhz is used. We have LoRa915, LoRa915-ANT, MOD-LoRa915, MOD-LoRa915-ANT.

At the moments we can’t offer EANT option for 915Mhz.

STMP157-SOM-EXT, STMP157-SOM-IND and STMP1(A13)-SOM-EVB are in stock!

Now our first STMP1 boards can be ordered on our web:

STMP1(A13)-SOM-EVB evaluation board (requires separate SOM)

STMP157-SOM-EXT extended temperature range -20+85C running on 800Mhz

STMP157-SOM-IND industrial temperature range -40+85C running on 650Mhz

Donald Knuth’s MIX computer implemented in iCE40HX8K-EVB

Donald Knuth’s “The Art of Computer Programming” is still a popular monograph which covers many types of programming algorithms and their analysis.

Although the first publishing was back in 1968, the book has been updated many times and is still a good source for learning algorithms.

Inside the book Knuth uses a hypothetical computer named MIX for writing all of his algorithms. The MIX computer has 9 registers and about 70 machine instructions.

Today in our Project section we got a submission of a MIX computer implementation on iCE40HX8K-EVB by Michael Schroeder.

The project is hosted on Gitlab:

https://gitlab.com/x653/mix-fpga

Several examples were created to demonstrate the MIX implementation such as generating the first 500 prime numbers.

The project is well documented and includes a manual: https://gitlab.com/x653/mix-fpga/-/raw/master/manual.pdf

Thanks Michael for the nice project!

We moved our irc chat channel #olimex to Libera.chat

Following the recent developments with Freenode we moved our IRC channel #olimex to Libera.chat.

You can access it via web or with other irc client.

May 2021 production delays and updates!

Everything is moving extra slowly this year.

On top of the Semiconductor shortages, now PCB factories also experience lack of raw materials and delay the production times more than double.

This is the reason our plans to release S3-OLinuXino, RK3328-SOM, STMP15x-OLinuXino-LIME2 and STM32MP15X-SOM to produced with delay.

At least we got the STMP15x-SOM and STMP1(A13)-EVB blank PCBs and by the end of next week they will be ready to order.

We used the time to update the product page with schematics and user manual.

Production updates for S3-OLinuXino, RK3328-SOM and STMP15x-OLinuXino-LIME2 will follow!