Menu
▾
▴
Tree [946586] dev / History
| File | Date | Author | Commit |
|---|---|---|---|
| templates | 2024-01-09 |
Wes Peters
|
[0c0c25] Refresh after reboot working, ready to test! |
| README.md | 2024-05-20 |
Wes Peters
|
[b74522] Sync pins configurations with documentation in ... |
| app.py | 2024-05-21 |
Wes Peters
|
[946586] Finish the startup wrangling - no need to use a... |
| cylon.py | 2024-05-21 |
Wes Peters
|
[40ad09] Add a test program to cycle the relays, also do... |
| db.sql | 2024-01-29 |
Wes Peters
|
[4b9c61] Fetching configuration from database and config... |
| pins16.json | 2024-05-20 |
Wes Peters
|
[7a155d] Typod port I |
| pins24.json | 2024-05-20 |
Wes Peters
|
[7a155d] Typod port I |
| pins8.json | 2024-05-20 |
Wes Peters
|
[eee6b6] Introduce the full relay object as a map |
| test.sql | 2024-01-29 |
Wes Peters
|
[4b9c61] Fetching configuration from database and config... |
Read Me
Raspberry Pi Modem PDU
The final design (for Viasat) is intended to use this relay module:
https://www.amazon.com/dp/B09YHD8R9F
These relay modules each contain 8 small 5VDC control relays with opto isolators on the inputs that provide both Normally Open (NO) and Normally Closed (NC) ports per relay. We use the NC ports, so that removing power to the Raspberry Pi and/or any relay boards will result in all associated ports being ON. This reverts to normal manual control (i.e. unplogging the modem) should the Raspberry Pi or one or more of the relay boards fail. One, two, or three relay modules may be installed per Raspberry Pi, offering 8, 16, or 24 switched ports.
The physical description of which relay modules have been installed must be provided in pins.json. The source includes examples pins8.json, pins16.json and pins24.json, for 1, 2, or 3 relay board configurations. When deploying a new build, copy one of these to pins.json. The only information needed in the pins file is a mapping of the external label, A, B, C, etc. to the I/O pin. The rest of the configuration pages will be keyed off the size of the pins array from this file.
On startup, the configuration database will be intialized with each port in the pins configuration labelled as "Port A," "Port B," etc. and the port turned ON.
The ON/OFF status is stored in the database so a reboot of the PDU will restore ports to their previous order. A REBOOT command doesn't change the database, as it is always a temporary state. If the PDU reboots while a device is being rebooted, the device should come up as ON following the reboot.
Raspberry Pi pinout diagrams include both the Broadcom numbering scheme, named GPIO.BCM by the GPIO library, as well as the Raspberry Pi board pin numbers, aka GPIO.BOARD. We use the GPIO BCM numbers in this configuration; Port A is Relay 0 on Module 0 and it is connected to GPIO14 so the pin is 14. The GPIO "BOARD" pins used per relay are:
| Label | Module | Port | Name | Pin | Pin | Name | Port | Module | Label |
|---|---|---|---|---|---|---|---|---|---|
| 3V3 | 1 | 2 | 5V | ||||||
| GPIO2 | 3 | 4 | 5V | ||||||
| GPIO3 | 5 | 6 | GND | ||||||
| GPIO4 | 7 | 8 | GPIO14 | 0 | 0 | A | |||
| 0 | GND | GND | 9 | 10 | GPIO15 | 1 | 0 | B | |
| D | 0 | 3 | GPIO17 | 11 | 12 | GPIO18 | 2 | 0 | C |
| E | 0 | 4 | GPIO27 | 13 | 14 | GND | GND | 0 | |
| F | 0 | 5 | GPIO22 | 15 | 16 | GPIO23 | 6 | 0 | G |
| 3V3 | 17 | 18 | GPIO24 | 7 | 0 | H | |||
| I | 1 | 0 | GPIO10 | 19 | 20 | GND | GND | 1 | |
| J | 1 | 1 | GPIO9 | 21 | 22 | GPIO25 | 2 | 1 | K |
| L | 1 | 3 | GPIO11 | 23 | 24 | GPIO8 | 4 | 1 | M |
| 1 | GND | GND | 25 | 26 | GPIO7 | 5 | 1 | N | |
| O | 1 | 6 | GPIO0 | 27 | 28 | GPIO1 | 7 | 1 | P |
| Q | 2 | 0 | GPIO5 | 29 | 30 | GND | GND | 2 | |
| R | 2 | 1 | GPIO6 | 31 | 32 | GPIO12 | 2 | 2 | S |
| T | 2 | 3 | GPIO13 | 33 | 34 | GND | GND | 2 | |
| U | 2 | 4 | GPIO19 | 35 | 36 | GPIO16 | 5 | 2 | V |
| W | 2 | 5 | GPIO26 | 37 | 38 | GPIO20 | 7 | 2 | X |
| 2 | GND | GND | 39 | 40 | GPIO21 |
This layout groups the header pins and leaves the I2C interface for a status display (optional).
