Wally exposes its signals via two 10-pin female headers (J1 and J5).
These headers are designed to accept a custom shield PCB on top. All key interfaces —
SPI, I²C, GPIO, and power — are accessible. Refer to the schematic for the complete
and exact pinout.
J1 — Left Header (10-pin)
| Pin |
Signal |
Function |
| 1 |
GPIO_5 |
SPI LoRa SS (chip select) |
| 2 |
GPIO_25 |
GPIO General purpose |
| 3 |
GPIO_19 |
SPI MISO (LoRa) |
| 4 |
SLEEP_SW |
Control Sleep switch (GPIO_26) |
| 5 |
LORA_DIO |
Control LoRa interrupt |
| 6 |
LORA_RST |
Control LoRa reset |
| 7 |
MODE |
GPIO Analog mode sense (GPIO_35) |
| 8 |
RTC_BATT |
GPIO RTC battery voltage (GPIO_39) |
| 9 |
V50 |
5V 5V supply rail |
| 10 |
GND |
GND Ground |
J5 — Right Header (10-pin)
| Pin |
Signal |
Function |
| 1 |
GPIO_32 |
GPIO General purpose / ADC |
| 2 |
GPIO_33 |
GPIO General purpose / ADC |
| 3 |
GPIO_18 |
SPI SCK (LoRa clock) |
| 4 |
GPIO_23 |
SPI MOSI (LoRa) |
| 5 |
TEMP |
1-Wire DS18B20 temperature |
| 6 |
SDA |
I²C I²C data (GPIO_21) |
| 7 |
SCL |
I²C I²C clock (GPIO_22) |
| 8 |
EN |
Control ESP32 enable / reset |
| 9 |
V50 |
5V 5V supply rail |
| 10 |
GND |
GND Ground |
All GPIO pins operate at 3.3V logic. Do not apply 5V signals directly to GPIO pins.
For the exact pinout including net names, refer to the Wally Schematic tab.
Wally is the Digital Stables main controller board — Rev 17.
It is the same board used inside every Daffodil unit, now available as a bare PCB for your own designs.
Rev 17 adds an onboard INA219 current/power monitor at the USB port for tracking USB power draw.
Compute & Radio
Core processing and wireless
| MCU | ESP32-WROOM-32E |
| LoRa | Ra-02 SX127x — 433 MHz, SPI |
| RTC | PCF8563T — I²C address 0x51 |
| USB | CP2110 USB-to-Serial — can be disconnected via jumper to eliminate standby current drain when running on solar |
| Temperature | DS18B20Z+ — 1-Wire |
| Regulator | AP7365 — 3.3V LDO |
| Current sense | INA219 — I²C, monitors USB port power (address 0x45) |
Interfaces & Control
Connectivity and on-board controls
| SPI bus | LoRa radio (SS GPIO_5, SCK GPIO_18, MISO GPIO_19, MOSI GPIO_23) |
| I²C bus | SDA GPIO_21, SCL GPIO_22 — shared with RTC |
| Sleep switch | TPS2051BDBVR load switch — GPIO_26 |
| Mode sense | Analog input GPIO_35 |
| Buttons | PROGRAM + RESET (TS-1095PS-A9B3-C3D2) |
| Headers | 2× 10-pin female (J1, J5) — shield interface |
I²C Bus — On-board Devices
| Address | Device |
|---|
0x51 | PCF8563T RTC |
0x45 | INA219 Current/Power Monitor — USB port (address pins A0 & A1 tied to V33) |
The I²C bus is exposed on J5 pins 6 & 7. Add your own sensors to the same bus on your shield.
Power
| Input | 5V via USB-C or shield header (V50) |
| Logic | 3.3V regulated (AP7365 LDO) |
| Sleep current | Controlled via TPS2051 load switch |
| Programming | USB — CP2104 auto-resets ESP32 |
Wally — Controller Board Schematic — Rev 17
Open PDF
Design resources to help you build a custom shield on top of Wally.
|
File |
Description |
Download |
|
|
WallyShieldTemplate.zip
KiCad 9 · ZIP archive
|
A KiCad 9 project template with the Wally header footprints pre-placed and wired.
Start your shield design here — J1 and J5 connector symbols, power nets, and a
board outline sized to match the Wally PCB are all included.
|
Download
|
|
|
Wally.ino
Arduino · ESP32
|
Hardware verification sketch. Tests the RTC (set & read time), LoRa 433 MHz
(TX/RX), DS18B20 temperature sensor, and watchdog WDI pulse.
Save into a folder named Wally/ before opening in Arduino IDE.
|
Download
|
