New Board with ESP32-S2 with LiPo charger unleash the native USB-OTG functionality

We recently released our ESP32-S2-DevKit-Lipo development board with ESP32-S2 SOC. It has the same functionality and pinout as Espressif ESP32-S2-Saola-1, but in addition it has a LiPo charger and battery management and is designed for Ultra low power – only 30uA consumption when on battery and deep sleep. This allows handheld battery operated applications. The LiPo part can power external sensors/circuits. This board has a built-in programmer with a CH340T USB-Serial convertor.

Many have noticed that ESP32-S2 has a native USB-OTG. Then why did we put the CH340T on it? The reason is that the Espressif SDK didn’t support USB back when we designed this board.

Now Espressif SDK adds support for a USB bootloader and the programming of the ESP32-S2 can be done by the native USB interface, we decided to make a new revision where the native USB-OTG interface is used.

We wanted to keep the LiPo battery functionality and this created an interesting technical challenge: the USB-OTG port can be used both as device and host. When used as a device, the board is powered by the USB and LiPo battery is charging. When used as a USB host (i.e. you can attach USB devices to the port) the USB port must supply 5V to the USB devices connected. Our first prototype had a power supply problem: when the ESP32-S2 works as a host the battery is powering the USB-OTG port with 5V, but there is attached also the LiPo charger circuit, so infinite loop is made: battery -> step up to 5V -> USB -> LiPo chgarger -> battery 🙂

This issue was preventing us from releasing this board earlier, but now on Rev.B all of these issues are fixed so we are about to run production.

Needless to say we kept the ultra low power design and the new board also consumes as low as 30uA in deep sleep.

Searching on the net it seems that no one else has implemented a USB-OTG functionality to the ESP32-S2 yet so this one will be the first. Also to the best of our knowledge there is still no software support for a USB host on the ESP32-S2 but we hope after our hardware is released this will push and accelerate the software development further.

ESP32-S2-DevKit-LiPo-USB is going to be released as Open Source Hardware like other IoT solutions we have.

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 .

ESP32-WROVER-DevKit-Lipo Open Source Hardware board with 4MB Flash and 8MB PSRAM is in stock

ESP32-WROVER-DevKit-Lipo

ESP32-WROVER-DevKit-LiPo is new open source hardware board which uses ESP32-WROVER modules with 4MB Flash and 8MB PSRAM.  It keeps same layout as ESP32-DevKit-C and ESP32-DevKit-Lipo, so boards made for these modules will work drop in.

The only difference between ESP32-WROOM and ESP32-WROVER modules beside the more RAM is that WROVER module has no GPIO16 and GPIO17 which are used internally and not connected to the outside pins.

New ESP32 Development board in stock ESP32-DevKit-Lipo target handheld applications with build in LiPo charger

ESP32-DevKit-LiPo

ESP32-DevKit-Lipo is pin to pin compatible with Espressif ESP32-CoreBoard (ESP32-DevKitC) board, but adds additional LiPo charger and battery connector, allowing board to work from LiPo battery when external power supply is missing.

Tomorrow 16.10 at SofUnitConf in Paradise Center in Sofia we will have Workshop with this board to show how easily it could be programmed with JavaScript and Espruino.

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

LIPO7000

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.

More LiPo battery models in stock 110mAh, 250mAh, 800mAh

800mah

For a while we were out of stock of our popular 1400mAh and 6600mAh LiPo batteries, but now they are back in stock.

We also have 4 new models:

110mAh with dimensions 30x17x3mm:

LiPo110mA

250mAh with dimensions: 27x21x5 mm:

lipo250mah

800mAh with dimensions: 50x30x5 mm:

lipo800mah

and 18650 type LiPo 2200mAh from the type used to build Laptop battery packs:

lipo2200mah

 

LiPo shipment problems with Airmail

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Ourr Aimail post service is delivered by DHL Global Mail. Yesterday we got notice that their scanner detected batteries in one of the shipment and they stop and return in back.

We have heard that some carrier refuse to deliver LiPo batteries are they are classified as dangerous goods, indeed LiPo batteries could cause fire if punched, LiPo are excluded as goods for DHL normal service too.

So far the road services like DPD and UPS Standard do not cause problems to ship batteries, but now we try to figure out how to exclude DHL and Airmail shipping as options when batteries are put in the basket for ordering. Until we come with solution we will just manually stop such orders, so please do not order batteries with DHL or Airmail unless you want your order to be put on hold.

 

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

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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

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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