Batteries and solar
Wait until active current, deep sleep and e-ink consumption are measured. Avoid unprotected cells and cheap charging modules.
Workbook / Shopping list
The first build kit.
A small, safe and understandable shopping list for three ESP32 nodes. It includes one spare node so troubleshooting does not stop when the first prototype needs to come alive.
- Three nodes
- One spare
- USB before batteries
01 / Core purchase
Order it now.
Prices are indicative Danish retail prices in DKK. Check availability, revision and datasheets before ordering.
| Part | Quantity | Estimated price | Requirement and note |
|---|---|---|---|
| ESP32-C6-DevKitC-1 | 4 | DKK 400-640 | Same variant, preferably 8 MB flash. Confirm pinout and Rust/ESP-IDF support. |
| 2.9" e-Paper Module | 4 | DKK 720-1,200 | Black and white, 296×128, SPI and 3.3 V logic. A module with driver and datasheet, not a bare panel. |
| Breadboard | 4 | DKK 100-160 | At least 400 connection points. |
| Dupont wires | 2 sets | DKK 80-140 | Mixed male-male, male-female and female-female. |
| USB-C cable | 4 | DKK 120-200 | Data and power cable, not charging only. |
| Tactile buttons | 10 | DKK 20-40 | 12 mm through-hole, momentary and normally open. |
| Pin headers | 1 pack | DKK 20-40 | 2.54 mm male and female for modules without soldered pins. |
| Passive buzzers | 4 | DKK 20-40 | 3.3-5 V for audible feedback. Optional in the first test. |
| Resistor assortment | 1 set | DKK 50-100 | Common 1/4 W resistors, especially 220 Ω, 1 kΩ and 10 kΩ. |
| Standoffs and mounting | 1 set | DKK 80-150 | M2/M3 for mounting the devkit and display without loose wires. |
02 / Power and measurement
Measure before buying batteries.
Start over USB until pinout and power consumption are known. A battery is not needed for the blink, display and radio tests.
| Part | Quantity | Estimated price | Requirement and note |
|---|---|---|---|
| USB power supply | 2 | DKK 100-200 | 5 V, at least 2 A and certified. Buy only if not already available. |
| USB power meter | 1 | DKK 100-200 | Displays voltage, current and accumulated energy. |
| Multimeter | 1 | DKK 300-800 | Must measure µA and mA with reasonably low burden voltage. |
A professional power profiler such as Nordic Power Profiler Kit II is better for deep-sleep measurements, but not required for the first bring-up.
03 / Wait with
Do not buy everything at once.
Field power, LoRa and a dedicated hub only make sense after the first measurements and decisions.
SX1262 and LoRa
Wait for module selection and checks of Danish/EU rules for 868 MHz, antennas and duty cycle.
Raspberry Pi hub
Use an existing laptop or mini-PC first. Buy a new hub only if a permanent machine is actually missing.
Custom PCB
Stay on breadboards and development boards until pinout, power and mechanics are verified.
04 / Before ordering
Five things to check.
- Choose one ESP32-C6 model and record its exact part number.
- Choose one e-ink model and confirm controller, resolution and existing driver support.
- Confirm that the e-ink module works with 3.3 V logic together with the ESP32-C6.
- Check stock and that the same revision can be reordered.
- Prefer a supplier with datasheets and returns over an anonymous marketplace listing without a model number.