LaskaKit ESP32-LPkit is a Czech board with the ESP32-WROOM-32E module designed for low power consumption: it has no USB-UART converter or LEDs that would draw current in deep sleep, and it has a Li-Ion cell charger and a low-quiescent regulator. Sensors connect to the μŠup connector, the remaining pins are on two rows of 16 pads.
Specifications
- ESP32 (ESP32-WROOM-32E module, or 32UE with IPEX): 2 cores 240 MHz, 4 MB flash
- Wi-Fi, Bluetooth
- headers J1 and J2 with 16 pads each (unpopulated), μŠup I2C (always-on 3.3 V)
- TP4054 charger (0.4 A, 0.26 / 0.5 A with a solder jumper), HT7833 regulator
- USB-C for charging only; uploading via the PROGRAM pads on the bottom or the LaskaKit CH9102 programmer
- 60 × 25 mm (the module antenna overhangs by about 5 mm)
The pinout applies to version 2.4 and is based on the LaskaKit schematic and Gerbers (the header silkscreen matches the copper). The diagram is drawn in portrait orientation with USB at the top – the manufacturing files show the board in landscape with USB-C on the left.
Battery measurement on GPIO34 has to be enabled by closing the ADC solder jumper on the board; the cell voltage is then the voltage on GPIO34 × 1.769. The VCC pin on header J1 is a power input only.
Pinout and pin table
Hover over a pin in the diagram or a table row; use the filter to highlight a bus. You can download the pinout as PNG or SVG.
| Pin | Name | Direction | UART | I2C | SPI | ADC | DAC | Touch | Note |
|---|---|---|---|---|---|---|---|---|---|
| Header J1 1 | VCC | input | Power input (3.5–5.5 V) – via diode D2 to the charger and regulator. USB-C does not feed this pin. | ||||||
| Header J1 2 | GPIO13 | input/output | ADC2_CH4 | T4 | JTAG MTCK | ||||
| Header J1 3 | GND | – | |||||||
| Header J1 4 | GPIO12 | input/output | ADC2_CH5 | T5 | Strapping pin (MTDI) – must be logic 0 at boot, otherwise the 3.3 V flash will not start | ||||
| Header J1 5 | GPIO14 | input/output | ADC2_CH6 | T6 | JTAG MTMS | ||||
| Header J1 6 | GPIO27 | input/output | ADC2_CH7 | T7 | |||||
| Header J1 7 | GPIO26 | input/output | ADC2_CH9 | DAC2 | |||||
| Header J1 8 | GPIO25 | input/output | ADC2_CH8 | DAC1 | |||||
| Header J1 9 | GPIO33 | input/output | ADC1_CH5 | T8 | |||||
| Header J1 10 | GPIO32 | input/output | ADC1_CH4 | T9 | |||||
| Header J1 11 | GPIO35 | input | ADC1_CH7 | Input only | |||||
| Header J1 12 | GPIO34 | input | ADC1_CH6 | Input only. Battery measurement through a 1 MΩ / 1.3 MΩ divider (Vbat = Vadc × 1.769) – connected only by the ADC jumper on the board, open from the factory. | |||||
| Header J1 13 | GPIO39 | input | ADC1_CH3 | ||||||
| Header J1 14 | GPIO36 | input | ADC1_CH0 | ||||||
| Header J1 15 | EN | input | Reset (RESET button) – logic 0 holds the ESP32 in reset | ||||||
| Header J1 16 | 3V3 | output | 3.3 V output from the HT7833 regulator (always on) | ||||||
| Header J2 1 | GND | – | |||||||
| Header J2 2 | GPIO23 | input/output | MOSI | ||||||
| Header J2 3 | GPIO22 | input/output | SCL | I2C SCL – also on the μŠup I2C connector. | |||||
| Header J2 4 | GPIO1 | input/output | TX | UART0 TX – upload via the PROGRAM pads | |||||
| Header J2 5 | GPIO3 | input/output | RX | UART0 RX – upload via the PROGRAM pads | |||||
| Header J2 6 | GPIO21 | input/output | SDA | I2C SDA – also on the μŠup I2C connector. | |||||
| Header J2 7 | GND | – | |||||||
| Header J2 8 | GPIO19 | input/output | MISO | ||||||
| Header J2 9 | GPIO18 | input/output | SCK | ||||||
| Header J2 10 | GPIO5 | input/output | SS | Strapping pin – level at boot (SDIO timing) | |||||
| Header J2 11 | GPIO17 | input/output | |||||||
| Header J2 12 | GPIO16 | input/output | |||||||
| Header J2 13 | GPIO4 | input/output | ADC2_CH0 | T0 | |||||
| Header J2 14 | GPIO0 | input/output | ADC2_CH1 | T1 | FLASH button. Strapping pin – logic 0 at boot = download mode | ||||
| Header J2 15 | GPIO2 | input/output | ADC2_CH2 | T2 | Strapping pin – logic 0 or unconnected at boot for download mode | ||||
| Header J2 16 | GPIO15 | input/output | ADC2_CH3 | T3 | Strapping pin – logic 0 at boot suppresses bootloader output | ||||
| μŠup I2C 1 | GND | – | |||||||
| μŠup I2C 2 | 3V3 | output | 3.3 V output from the HT7833 regulator (always on) | ||||||
| μŠup I2C 3 | GPIO21 | input/output | SDA | I2C SDA – also on the μŠup I2C connector. | |||||
| μŠup I2C 4 | GPIO22 | input/output | SCL | I2C SCL – also on the μŠup I2C connector. | |||||
| Battery 1 | BAT+ | input/output | 3.7 V Li-Ion / Li-Pol cell (charged by TP4054) | ||||||
| Battery 2 | GND | – |
Pins used on the board
These chip pins are used by parts on the board and are not broken out:
| Pin | Function on the board |
|---|---|
| GPIO6–11 | Module flash (not broken out) |
| PROGRAM | Pads underneath: RTS, DTR, TX, RX, GND, 3V3 and USB D+/D− – for the LaskaKit CH9102 programmer (then you can also upload via USB-C) |
What to watch out for
- The GPIO are not 5V tolerant.
- GPIO12 must be at logic 0 at boot (flash voltage strapping pin); GPIO0, 2, 5 and 15 are also strapping pins.
- GPIO34–39 are input-only with no pull-up.
- The ADC solder jumper for battery measurement is open from the factory.
- The VCC pin is not a 5 V output – no voltage reaches it from USB-C.
ESP32 on chiptron.eu/
Projects and guides on chiptron.eu/:
- ESP32 chip comparison – recommended boards for battery-powered use
More pinouts
See all pinouts on the Pinouts page.