IMBRIOS LOGSENS_V1P1

ESP32-based environmental sensing board - designed for data logging and remote monitoring systems.

Micro-USB
IMBRIOS LOGSENS_V1P1 board
ESP32
MCU
240MHz
clock
4MB
flash
520KB
SRAM
23· 7 ADC
GPIO
BLE 4.2+ WiFi
radio
On this page

IMBRIOS LOGSENS_V1P1 Pinout

25 pins
PinGPIOLabelsStatusCapabilitiesNotes
10SW2_BUILDINstrapping-
21TXPWMuartuart
32A12T2PWMstrappingadc · touch
43RXPWMuartuart
54UART2_RTSCAN_TXDEPWMsafe-
612MISOPWMstrappingspi
713MOSIPWMstrappingspi
814SCKPWMstrappingspi
915SSA13T3PWMstrappingadc · touch · spi
1016UART2_RXCAN_RXPWMsafe-
1117UART2_TXCAN_TXPWMsafe-
1219BUZZER_CTRLPWMsafe-
1321SDAPWMsafei2c
1422SCLPWMsafei2c
1523SPI_SS1PWMsafe-
1625A18DAC1PWMsafeadc · dac
1726A19DAC2PWMsafeadc · dac
1827A17T7PWMsafeadc · touch
1932A4T9PWMsafeadc · touch
2033LED_BUILTINA5T8PWMsafeadc · touch
2134SW4_BUILDINstrapping-
2235SD_CARD_DETECTstrapping-
2336SW3_BUILDINstrapping-
24-LED1_BUILDINsafe-
25-LED2_BUILDINsafe-
23 GPIOs broken out 12 free · 11 need care · 0 to avoid

Start with these

12 pins with no boot or system involvement
UART2_RTSGPIO4UART2_RXGPIO16UART2_TXGPIO17BUZZER_CTRLGPIO19SDAGPIO21SCLGPIO22SPI_SS1GPIO23A18GPIO25A19GPIO26A17GPIO27A4GPIO32LED_BUILTINGPIO33

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

11 pins · 11 things to know
SW2_BUILDINGPIO0 Bootstrapping pin (enter bootloader when low); internal pull-up. Strapping

Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.

TXGPIO1 Default UART0 TX pin for USB-serial programming and console. UART

Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.

A12GPIO2 Bootstrapping pin (must be low or floating at reset); internal pull-down. Strapping

If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.

RXGPIO3 Default UART0 RX pin for USB-serial programming (console input). UART

Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.

MISOGPIO12 Bootstrapping pin; JTAG TDI; sets flash voltage (VDD_SDIO); also HSPIQ (flash data line). Strapping

Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.

MOSIGPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG

Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.

SCKGPIO14 JTAG mode select pin (TMS); also HSPI CLK and PWM-capable GPIO. JTAG

Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.

SSGPIO15 Bootstrapping pin; JTAG TDO; controls UART0 boot log output; also HSPICS0 (secondary SPI CS). Strapping

Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.

SW4_BUILDINGPIO34 Input-only GPIO (no output driver); ADC1 channel 6. Other

Cannot be used as output (no drive capability); only suitable for analog/digital input.

SD_CARD_DETECTGPIO35 Input-only GPIO (no output driver); ADC1 channel 7. Other

Cannot be used as output; only suitable for input.

SW3_BUILDINGPIO36 Input-only GPIO (no output); ADC1 channel 0, Hall sensor VP. Other

Cannot be used as output; only suitable for input (e.g., analog read).

These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.

The IMBRIOS LOGSENS_V1P1 breaks out 25 pins in total: 23 GPIO for your project.

For peripherals, I²C is mapped to SDA on GPIO21 and SCL on GPIO22; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO1 and GPIO3 cover serial logging and flashing.

On the analog side there are 7 ADC-capable pins for sensors and battery monitoring, 5 capacitive-touch inputs and 2 true DAC outputs.

If you want zero surprises, UART2_RTS, UART2_RX, UART2_TX, BUZZER_CTRL and 8 more are free of any such role - the safest first picks. 11 of the exposed pins carry boot-time or system duties on the ESP32 (SW2_BUILDIN, TX, A12 and 8 more).

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Install your USB-serial driver (CH340 / CP210x) if no port appears. Not detected? Hold BOOT while plugging in.
2
Match & flash
Set the Tools options shown, then click Upload.
3
Verify it runs
GPIO4 toggles - wire an LED and resistor to it, or change the pin to your board's own LED.
Set these in Tools · leave everything else at default
Arduino IDE 2.x - Tools Copy
Board: "ESP32 Dev Module"▸
Flash Size: "4MB (32Mb)"▸
Flash Mode: "DIO"▸
Partition Scheme: "Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)" (default)▸
Upload Speed: "921600"▸
▸ every other Tools option - leave at default
Board: ESP32 Dev Module
Flash Size: 4MB (32Mb)
Flash Mode: DIO
Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
Upload Speed: 921600
Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32 Dev Module
blink.ino Copy
// toggle GPIO4 - wire an LED and resistor to it
void setup() {
  pinMode(4, OUTPUT);
}
void loop() {
  digitalWrite(4, HIGH); delay(500);
  digitalWrite(4, LOW);  delay(500);
}
board to selectesp32dev⧉ copy
platformio.ini Copy
[env:imbrios-logsens-v1p1]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600
Find it: PlatformIO Home ▸ Boards, search esp32dev - or type it after board =.
board to selectesp32dev⧉ copy
device.yaml Copy
esp32:
  board: esp32dev
  variant: esp32
  framework:
    type: esp-idf

# blink - GPIO4
output:
  - platform: gpio
    pin: 4
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out
Find it: search ESPHome's board list for esp32dev (same ids as PlatformIO).
esptool doesn't pick board settings - a prebuilt .bin already has them baked in. This is just the raw flash command.
terminal Copy
esptool.py --chip esp32 --port /dev/ttyACM0 \
  --baud 921600 write_flash 0x1000 firmware.bin
--port = your /dev/tty* (macOS/Linux) or COMx (Windows).
Build details: sketch space 1310720 B · data 327680 B · DIO

Specifications

ESP32 · vs other ESP32 chips →
Compute
MCU
ESP32
Clock
240 MHz
SRAM · Flash
520 KB · 4MB
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
4.2 LE
Antenna
PCB
I/O
GPIO · ADC
23 · 7
UART · I²C · SPI
3 · 2 · 2
PWM
16 channels
Power
USB
Micro-USB
Serial
-
Boot address
0x1000
Electrical
Input
7-45V DC
Consumption
-
Regulator
-
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · DIO
Sketch · Data
1.25 MB · 320 KB
The IMBRIOS LOGSENS_V1P1 uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with DIO boot mode. The maximum sketch size is 1.25 MB with 320 KB available for data.

About this board

At its core is the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.

Onboard you'll find a microSD slot, a Grove connector, an RTC, a buzzer, an RS485 interface and a CAN bus interface.

Resources

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