| BB-leds | |
|---|---|
 | |
| Participants | |
| Skills | Electronics |
| Status | Getting parts |
| Niche | Hardware |
| Purpose | Fun |
| Tool | No |
| Location | shelves next to studio |
| Cost | |
| Tool category | General |
bb-leds-power.jpg {{#if:No | [[Tool Owner::{{{ProjectParticipants}}} | }} {{#if:No | [[Tool Cost::{{{Cost}}} | }}
Monochrome LED tickers donated from ]LAG[
- 2 boards * 3 text lines * 7 rows * 90 columns
- Boards have been reverse-engineered (TODO document on wiki)
- One board is missing the PNP transistor for one of the seven rows
2023-01-01 First attempt to power up one of the boards (the one that isn't missing one of its transistors) using variable power supply failed, high current draw (0.5A) was observed at only a few volts. One of the two tantalum caps is the main suspect, further investigation needed. Other board not yet tested.
beaglebone
2022-12-31 Flashed with a basic debian bullseye system.
- hostname:
bb-leds - login:
debian - password:
777
This beaglebone is missing its mini-usb port but can be powered via the P9 header e.g. using included cable (see photo).
For reference, the power pins of the beaglebone:
- P9.01 + P9.02 = GND
- P9.03 + P9.04 = 3.3V out (unused)
- P9.05 + P9.06 = 5V in
- P9.07 + P9.08 = 5V out (to level shifter)
level shifter
A 3.3V to 5V level shifter is needed (3 signals per board, can probably be optimized to 4 signals total for both boards if they're driven synchronously). As a temporary hack a beestore pro mini from User:flok has been programmed to act as a 6-ch level shifter with following pinout:
- PC0 ("A0") → PB0 ("D8")
- PC1 ("A1") → PB1 ("D9")
- PC2 ("A2") → PB2 ("D10")
- PC3 ("A3") → PB3 ("D11")
- PC4 ("A4/SCL") → PB4 ("D12")
- PC5 ("A5/SDA") → PB5 ("D13")