New Open Source Hardware IoT ESP32-S2 development boards with LiPo Battery Charger and consumption of only 30uA in deep sleep target handheld WiFi apps

ESP32-S2 is new SOC from Espressif which fills the gap between ESP32 and ESP8266.

It has the same memory model as ESP32 but has cut the Ethernet and Bluetooth parts, so only WiFi connection is possible – same as ESP8266, but offers more power, secure boot and encrypted firmware. Also support of decent SSL connection, something which lacks in ESP8266.

Pricewise now S2 is a bit lower cost than ESP32 and more expensive than ESP8266, but there is very strong competition in this niche coming from the new Bouffalo BL6XX chips, so my prediction is that to stay ahead Espressif will further lower the prices of ESP32-S2 to match ESP8266 very soon.

For comparison with ESP32 and ESP8266 the new ESP32-S2 has plenty of GPIOs up to 43!

Initially Espressif has announced that their ESP32-S2-WROVER modules will have as low as 2-4uA consumption, but later they increased this value to 20uA. Not quite well as their target but still very good achievement.

Our ESP32-S2-DevKit-Lipo is pin to pin compatible with ESP32-S2-Saola-1:

To keep compatibility with SAOLA-1 we add RGB LED, but also add LiPo battery charger and ESP32-S2-DevKit-Lipo can operate even without external power supply only on LiPo battery, there is battery level monitoring and external power supply sense. ESP32-S2-DevKit-Lipo can power external circuits with 3.3V up to 200mA when operate on battery.

ESP32-S2-DevKit-Lipo has build in programmer with CH340T. There is possibility the programmer part to be excluded and to use ESP32-S2 directy USB connection.

When operating on battery if the RGB LED is enabled the power consumption is ridiculous 700uA as the RGB LED appear to use lot of current even when not in operation, but there is RGB disable solder jumper which if opened you will not be able to operate the RGB LED on battery but will decrease the power consumption to total less 30uA in deep sleep.

For these who need more memory there is variant ESP32-S2-WROVER-DevKit-Lipo with 2MB of PSRAM.

The prices start from EUR 5.56 for ESP32-S2-DevKit-Lipo and EUR 6.36 for ESP32-S2-WROVER-DevKit-Lipo .

Open Source Hardware ESP32-POE-ISO is now in stock and we are very proud with the result

We are very proud of our new ESP32-POE-ISO and delighted to announce it’s already in stock ready for order!

What we did with this improved version of the low cost ESP32-POE power over ethernet solution for IoT?

1. As many requested we add 3000VDC galvanic insulation. Now you can program / debug while connected to PoE switch or router;
2. Many asked for more GPIOs so we set SD-card in 1 bit mode and this way released 3 GPIO pins for other use;
3. We got hints that new Espressif SDK allow ultra deep sleep modes for ESP32 and we re-designed the power supply part that now the ESP32-POE-ISO has consumption down to 200 uA (130uA of which are taken from ESP32-WROOM-32D module). The rest board without the module consumes just 70uA;
4. As per your request now battery level has option to be monitored with the ESP32 ADC;
5. There is External power detection option, so your software will be aware when run sole on battery and when have plenty of power.
6. The Isolated DCDC we use is 2W and provides 400mA @5V, 100mA are reserved for the battery charge (available if no battery is connected) and 100mA are provided for ESP32, which leaves up to 200mA @5V for your additional circuit.

We love to listen to our customers and we did our the best to complete most of the requests we got with this new version.

OLIMEXINO-328 special version of Arduino made for low power battery applications

Our friends from IrDroid made evaluation of OLIMEXINO-328 board low power modes and blogged about it.

OLIMEXINO-328 is special version of Arduino made for Industrial applications – It can be powered from 9 to 30VDC. The board has build in LiPo charger and step up convertor so when external power is applied or connected to USB the LiPo battery is charged, if both External power and USB connection is missing the power supply is automatically back up by the LiPo battery and OLIMEXINO-328 keep running from battery.

All components of OLIMEXINO-328 work in temperature range -25+85C.

Low power voltage regulators are used to board can be bring down to few micro Ampers when not active.

New product in stock: 7000 mAh LiPo battery with JST connector

BATTERY-LiPo7000mAh is re-chargable Lithium Polymer battery with over voltage and under voltage protection circuit and JST connector for all our OLinuXino, OLIMEXINO, PINGUINO, Duinomite boards.

This battery when attached to OLinuXino OSHW computers will allow them to run without external power supply for all day long. Normally OLinuXino consumption is between 0.2 and 0.5A depend on workload this means with this battery fully charged they will work between 14-35 hours stand alone.

Note that these LiPo batteries are considered dangerous for transportation and we can ship them only with ground service like DPD, UPS Standard, TNT Economy, which limits the shipping options to just EU.

Experimenting with low power modes and Arduino

Tero Koskinen recently did interesting experiments exploring how low power he can go with Arduino. http://arduino.ada-language.com/saving-power-with-avr-ada.html

He made setup with 5 boards to test:

• original Arduino Duemilanove
• original Arduino UNO
• Olimexino-328 clone
• Arduino DIY PTH kit from Sparkfun
• Diavolino from Evil Mad Scientist

He correctly shut down all not used peripherials, Brown-Out-Detection, slowed down the CPU speed and used Power Saving modes.

the results were:

Device	Current
Duemilanove	7.50mA
UNOr3	18.10mA
Olimexino-328	4.00mA
Sparkfun PTH Kit	7.60mA
Diavolino	0.50mA

 

Diavolino have nothing but the AVR so obviously is winner with this setup with only 0.5mA consumption.

Wait if there is no power regulator where these 0.5mA go when AVR is put in low power mode?

Looking at the schematic  you can see R1 RESET pullup 10K resistor which is connected to 5V -> 5V/10K = 0.5mA the whole consumption is taken by R1!!!

 

Then let’s see OLIMEXINO-328 the second place with 4mA (outch!) this board is promoted by OLIMEX as SUPER DUPER LOW POWER BOARD then why these bad results? Where these  4mA go?

The answer is obvious: Tero is powering OLIMEXINO-328 by the POWER JACK.

In our design we assume if the power come from the power jack it’s unlimited and we can waste it as much as we need – charging Lipo (if attached) etc.

So these 4mA are taken from the DCDC in the input.

If Tero wanted to see how OLIMEXINO-328 shines in low power he should have powered the board by the battery connector. When the power is applied to battery OLIMEXINO-328 is very humble and will need less 20 micro ampers 0.02 mA to operate!

How this is done? If we look at the schematic we will see that there is no RESET pull-up, but the RESET is done by tricky circuit with R12/R13/SD5/C7/C8 this schematic have zero consumption but still perform RESET functionality.

Also unltra-low-power LDO which needs just 3 micro amps to operate MCP1700T-3302E/MB is used for power regulator.

This makes possible complete Arduino to may keep working while consuming less 20 micro amps.

What 20 micro amps consumption means? If you use our standard LiPo 1400 mAh battery your board can work 70 000 hours or 3 years!

The other boards: Sparkfun kit 7.6 mA, Duemilanove 7.5mA and UNO 18.1 mA just use cheap voltage regulators which take this current, but it’s OK they have not been designed to be low power.

What is the conclusion: with right setup (powering from battery) OLIMEXINO-328 is the lowest power Arduino solution on the market! When we add to the low power the industrial temperature operation range -25+85C and the possibility to work with any input voltages from 9 to 30VDC, OLIMEXINO-328 is the most sophisticated board with many features while keeping the price reasonable.

New Products in stock: Lithium Polymer batteries: 3000mAh, 4400mAh, 6600mAh

We got in stock three new types of Lithium Polymer batteries: 3000mAh, 4400mAh and 6600mAh, all they are 3.7V and compatible with all our boards with LiPo chargers like: OLinuXino A13, A20, Olimexino-328, Olimexino-STM32, Pinguino etc.

6600mAh is real monster and can backup as UPS A13-OLinuXino to work without external voltage for 20 hours under full load.

The products are available in our web shop in Power supply category: https://www.olimex.com/Products/Power/

All battery packs have protection circuit for over-voltage and short-circuit.

A13-OLinuXino REV.B works fine from LiPo battery

At first we couldn’t decide if we should make A13-OLinuXino to work from Li-Po battery,  this seemed to be just increase of the BOM and price, so we made REV.A without this feature.

Later though we decided that this is nice feature and we re-considered and included this feature in Rev.B

Now A13-OLinuXino Rev.B is assembling and we got some of the first boards to test with LiPo battery, the result is A13-OLinuXino now may run from single LiPo and support USB devices too thanks to the included boost DCDC.

EDIT:

Some current measurements were taken while board was powered with 3.7V standard 1400mAh LiPo battery we have.

Without LCD the board running Android consumes between 200 and 550mA depend on the different activities, when LCD is add the consumption rise with 450mA due to the backlight.

When the board is in power safe mode the consumption drops to 3mA.

So the A13 while running at 1Ghz takes just 2W power

iMX233 battery power supply tests

Once we solved all battery power supply issues on iMX233-OLinuXino-Maxi today we tested how it works with our Li-Po battery http://www.olimex.com/dev/battery-lipo1400mah.html

We got very interesting results!

The LAN9512 USB hub + Ethernet takes about 250mA when used, total consumption is around 320 mA when all peripherials are used and Ethernet is working with the 1400mA battery this means around 4 hours of continuous operation on backup battery for iMX233-OLinuXino-Maxi.

Then we disconnected the LAN9512 to see how power hungry will be iMX233-OLinuXino-Mini and whoa during the boot the consumption is around 120mA, then at linux console working with the board the power consumption drop to 75mA! this means about 18 hours work on battery! Then we put the board in suspend mode with the PWR/REC button in this mode the processor is IDLE and just the RAM is refreshing, and the power went down to 30mA.

Now I’m really puzzled does 454Mhz ARM926J processor consumes only 45mA when run at full speed?

On Linux console running “top” show CPU use 3% when you do simple shell commands. So let’s make the CPU a bit busy with:

$ cat /dev/urandom > /dev/null &

$ top

Now we see CPU is used at 100% and the power consumption rise from 75 to 120mA! Ahaaa so Linux kernel does some kind of flexible power management depend on the CPU load, so the power consumption vary. Anyway if we assume the DDR still takes about 30mA the power consumtion of just 45-90mA of 454Mhz ARM9 processor is remarkable (well let’s not forget that iMX233 was designed with portable media player in mind so working on battery was design goal for the engineers who created it, well done!).

Conclusions:

1. on battery with USB hubs ON, Ethernet ON etc. the total power consumption is about 1.35W (4.2V x 0.32A)

2. without LAN9512 USB hubs and Ethernet the total power vary from 0.3W to 0.5W depend on CPU load

3. In suspend mode OLinuXino needs just 0.1W