forked from M-Labs/thermostat
290 lines
14 KiB
Markdown
290 lines
14 KiB
Markdown
# Firmware for the Sinara 8451 Thermostat
|
|
|
|
- [x] [Continuous Integration](https://nixbld.m-labs.hk/job/mcu/thermostat/thermostat)
|
|
- [x] Download latest firmware build: [ELF](https://nixbld.m-labs.hk/job/mcu/thermostat/thermostat/latest/download/1) [BIN](https://nixbld.m-labs.hk/job/mcu/thermostat/thermostat/latest/download/2)
|
|
|
|
|
|
## Building
|
|
|
|
### Reproducible build with Nix
|
|
|
|
Thermostat firmware is packaged using the [Nix](https://nixos.org) Flakes system. Install Nix 2.4+ and enable flakes by adding ``experimental-features = nix-command flakes`` to ``nix.conf`` (e.g. ``~/.config/nix/nix.conf``).
|
|
|
|
Once you have Flakes enabled, you can use ``nix build`` to build the firmware.
|
|
|
|
### Development environment
|
|
|
|
Clone this repository and with Nix Flakes enabled, use the following commands:
|
|
|
|
```shell
|
|
nix develop
|
|
cargo build --release
|
|
```
|
|
|
|
The resulting ELF file will be located under `target/thumbv7em-none-eabihf/release/thermostat`.
|
|
|
|
Alternatively, you can install the Rust toolchain without Nix using rustup; see the Rust manifest file pulled in `flake.nix` to determine which Rust version to use.
|
|
|
|
## Debugging
|
|
|
|
Connect SWDIO/SWCLK/RST/GND to a programmer such as ST-Link v2.1. Run OpenOCD:
|
|
```shell
|
|
openocd -f interface/stlink.cfg -f target/stm32f4x.cfg
|
|
```
|
|
|
|
You may need to power up the programmer before powering the device.
|
|
Leave OpenOCD running. Run the GNU debugger:
|
|
```shell
|
|
gdb target/thumbv7em-none-eabihf/release/thermostat
|
|
|
|
(gdb) source openocd.gdb
|
|
```
|
|
|
|
## Flashing
|
|
There are several options for flashing Thermostat. DFU requires only a micro-USB connector, whereas OpenOCD needs a JTAG/SWD adapter.
|
|
|
|
### dfu-util on Linux
|
|
* Install the DFU USB tool (dfu-util).
|
|
* Convert firmware from ELF to BIN: `arm-none-eabi-objcopy -O binary thermostat thermostat.bin` (you can skip this step if using the BIN from Hydra)
|
|
* Connect to the Micro USB connector to Thermostat below the RJ45.
|
|
* Add jumper to Thermostat v2.0 across 2-pin jumper adjacent to JTAG connector.
|
|
* Cycle board power to put it in DFU update mode
|
|
* Push firmware to flash: `dfu-util -a 0 -s 0x08000000:leave -D thermostat.bin`
|
|
* Remove jumper
|
|
* Cycle power to leave DFU update mode
|
|
|
|
### st.com DfuSe tool on Windows
|
|
On a Windows machine install [st.com](https://st.com) DfuSe USB device firmware upgrade (DFU) software. [link](https://www.st.com/en/development-tools/stsw-stm32080.html).
|
|
- add jumper to Thermostat v2.0 across 2-pin jumper adjacent to JTAG connector
|
|
- cycle board power to put it in DFU update mode
|
|
- connect micro-USB to PC
|
|
- use st.com software to upload firmware
|
|
- remove jumper
|
|
- cycle power to leave DFU update mode
|
|
|
|
### OpenOCD
|
|
```shell
|
|
openocd -f interface/stlink.cfg -f target/stm32f4x.cfg -c "program target/thumbv7em-none-eabihf/release/thermostat verify reset;exit"
|
|
```
|
|
|
|
## Network
|
|
|
|
### Connecting
|
|
|
|
Ethernet, IP: 192.168.1.26/24
|
|
|
|
Use netcat to connect to port 23/tcp (telnet)
|
|
```sh
|
|
rlwrap nc -vv 192.168.1.26 23
|
|
```
|
|
|
|
telnet clients send binary data after connect. Enter \n once to
|
|
invalidate the first line of input.
|
|
|
|
|
|
### Reading ADC input
|
|
|
|
Set report mode to `on` for a continuous stream of input data.
|
|
|
|
The scope of this setting is per TCP session.
|
|
|
|
|
|
### TCP commands
|
|
|
|
Send commands as simple text string terminated by `\n`. Responses are
|
|
formatted as line-delimited JSON.
|
|
|
|
| Syntax | Function |
|
|
|----------------------------------|-------------------------------------------------------------------------------|
|
|
| `report` | Show current input |
|
|
| `report mode` | Show current report mode |
|
|
| `report mode <off/on>` | Set report mode |
|
|
| `pwm` | Show current PWM settings |
|
|
| `pwm <0/1> max_i_pos <amp>` | Set maximum positive output current |
|
|
| `pwm <0/1> max_i_neg <amp>` | Set maximum negative output current |
|
|
| `pwm <0/1> max_v <volt>` | Set maximum output voltage |
|
|
| `pwm <0/1> i_set <amp>` | Disengage PID, set fixed output current |
|
|
| `pwm <0/1> pid` | Let output current to be controlled by the PID |
|
|
| `center <0/1> <volt>` | Set the MAX1968 0A-centerpoint to the specified fixed voltage |
|
|
| `center <0/1> vref` | Set the MAX1968 0A-centerpoint to measure from VREF |
|
|
| `pid` | Show PID configuration |
|
|
| `pid <0/1> target <deg_celsius>` | Set the PID controller target temperature |
|
|
| `pid <0/1> kp <value>` | Set proportional gain |
|
|
| `pid <0/1> ki <value>` | Set integral gain |
|
|
| `pid <0/1> kd <value>` | Set differential gain |
|
|
| `pid <0/1> output_min <amp>` | Set mininum output |
|
|
| `pid <0/1> output_max <amp>` | Set maximum output |
|
|
| `s-h` | Show Steinhart-Hart equation parameters |
|
|
| `s-h <0/1> <t0/b/r0> <value>` | Set Steinhart-Hart parameter for a channel |
|
|
| `postfilter` | Show postfilter settings |
|
|
| `postfilter <0/1> off` | Disable postfilter |
|
|
| `postfilter <0/1> rate <rate>` | Set postfilter output data rate |
|
|
| `load [0/1]` | Restore configuration for channel all/0/1 from flash |
|
|
| `save [0/1]` | Save configuration for channel all/0/1 to flash |
|
|
| `reset` | Reset the device |
|
|
| `dfu` | Reset device and enters USB device firmware update (DFU) mode |
|
|
| `ipv4 <X.X.X.X/L> [Y.Y.Y.Y]` | Configure IPv4 address, netmask length, and optional default gateway |
|
|
| `fan` | Show current fan settings and sensors' measurements |
|
|
| `fan <value>` | Set fan power with values from 1 to 100 |
|
|
| `fan auto` | Enable automatic fan speed control |
|
|
| `fcurve <a> <b> <c>` | Set fan controller curve coefficients (see *Fan control* section) |
|
|
| `fcurve default` | Set fan controller curve coefficients to defaults (see *Fan control* section) |
|
|
| `hwrev` | Show hardware revision, and settings related to it |
|
|
|
|
|
|
## USB
|
|
|
|
The firmware includes experimental support for acting as a USB-Serial
|
|
peripheral. Debug logging will be sent there by default (unless build
|
|
with logging via semihosting.)
|
|
|
|
**Caveat:** This logging does not flush its output. Doing so would
|
|
hang indefinitely if the output is not read by the USB host. Therefore
|
|
output will be truncated when USB buffers are full.
|
|
|
|
|
|
## Temperature measurement
|
|
|
|
Connect the thermistor with the SENS pins of the
|
|
device. Temperature-depending resistance is measured by the AD7172
|
|
ADC. To prepare conversion to a temperature, set the Beta parameters
|
|
for the Steinhart-Hart equation.
|
|
|
|
Set the base temperature in degrees celsius for the channel 0 thermistor:
|
|
```
|
|
s-h 0 t0 20
|
|
```
|
|
|
|
Set the resistance in Ohms measured at the base temperature t0:
|
|
```
|
|
s-h 0 r0 10000
|
|
```
|
|
|
|
Set the Beta parameter:
|
|
```
|
|
s-h 0 b 3800
|
|
```
|
|
|
|
### 50/60 Hz filtering
|
|
|
|
The AD7172-2 ADC on the SENS inputs supports simultaneous rejection of
|
|
50 Hz ± 1 Hz and 60 Hz ± 1 Hz (dB). Affecting sampling rate, the
|
|
postfilter rate can be tuned with the `postfilter` command.
|
|
|
|
| Postfilter rate | Rejection | Effective sampling rate |
|
|
| --- | :---: | --- |
|
|
| 16.67 Hz | 92 dB | 8.4 Hz |
|
|
| 20 Hz | 86 dB | 9.1 Hz |
|
|
| 21.25 Hz | 62 dB | 10 Hz |
|
|
| 27 Hz | 47 dB | 10.41 Hz |
|
|
|
|
## Thermo-Electric Cooling (TEC)
|
|
|
|
- Connect TEC module device 0 to TEC0- and TEC0+.
|
|
- Connect TEC module device 1 to TEC1- and TEC1+.
|
|
- The GND pin is for shielding not for sinking TEC module currents.
|
|
|
|
When using a TEC module with the Thermostat, the Thermostat expects the thermal load (where the thermistor is located) to cool down with a positive software current set point, and heat up with a negative current set point.
|
|
|
|
Testing heat flow direction with a low set current is recommended before installation of the TEC module.
|
|
|
|
### Limits
|
|
|
|
Each of the MAX1968 TEC driver has analog/PWM inputs for setting
|
|
output limits.
|
|
|
|
Use the `pwm` command to see current settings and maximum values.
|
|
|
|
| Limit | Unit | Description |
|
|
| --- | :---: | --- |
|
|
| `max_v` | Volts | Maximum voltage |
|
|
| `max_i_pos` | Amperes | Maximum positive current |
|
|
| `max_i_neg` | Amperes | Maximum negative current |
|
|
| `i_set` | Amperes | (Not a limit; Open-loop mode) |
|
|
|
|
Example: set the maximum voltage of channel 0 to 1.5 V.
|
|
```
|
|
pwm 0 max_v 1.5
|
|
```
|
|
|
|
Example: set the maximum negative current of channel 0 to -3 A.
|
|
```
|
|
pwm 0 max_i_neg 3
|
|
```
|
|
|
|
Example: set the maximum positive current of channel 1 to 3 A.
|
|
```
|
|
pwm 0 max_i_pos 3
|
|
```
|
|
|
|
### Open-loop mode
|
|
|
|
To manually control TEC output current, omit the limit parameter of
|
|
the `pwm` command. Doing so will disengage the PID control for that
|
|
channel.
|
|
|
|
Example: set output current of channel 0 to 0 A.
|
|
```
|
|
pwm 0 i_set 0
|
|
```
|
|
|
|
## PID-stabilized temperature control
|
|
|
|
Set the target temperature of channel 0 to 20 degrees celsius:
|
|
```
|
|
pid 0 target 20
|
|
```
|
|
|
|
Enter closed-loop mode by switching control of the TEC output current
|
|
of channel 0 to the PID algorithm:
|
|
```
|
|
pwm 0 pid
|
|
```
|
|
|
|
## LED indicators
|
|
|
|
| Name | Color | Meaning |
|
|
| --- | :---: | --- |
|
|
| L1 | Red | Firmware initializing |
|
|
| L3 | Green | Closed-loop mode (PID engaged) |
|
|
| L4 | Green | Firmware busy |
|
|
|
|
## Reports
|
|
|
|
Use the bare `report` command to obtain a single report. Enable
|
|
continuous reporting with `report mode on`. Reports are JSON objects
|
|
with the following keys.
|
|
|
|
| Key | Unit | Description |
|
|
| --- | :---: | --- |
|
|
| `channel` | Integer | Channel `0`, or `1` |
|
|
| `time` | Seconds | Temperature measurement time |
|
|
| `adc` | Volts | AD7172 input |
|
|
| `sens` | Ohms | Thermistor resistance derived from `adc` |
|
|
| `temperature` | Degrees Celsius | Steinhart-Hart conversion result derived from `sens` |
|
|
| `pid_engaged` | Boolean | `true` if in closed-loop mode |
|
|
| `i_set` | Amperes | TEC output current |
|
|
| `dac_value` | Volts | AD5680 output derived from `i_set` |
|
|
| `dac_feedback` | Volts | ADC measurement of the AD5680 output |
|
|
| `i_tec` | Volts | MAX1968 TEC current monitor |
|
|
| `tec_i` | Amperes | TEC output current feedback derived from `i_tec` |
|
|
| `tec_u_meas` | Volts | Measurement of the voltage across the TEC |
|
|
| `pid_output` | Amperes | PID control output |
|
|
|
|
Note: With Thermostat v2 and below, the voltage and current readouts `i_tec` and `tec_i` are disabled and null due to faulty hardware that introduces a lot of noise in the signal.
|
|
|
|
## PID Tuning
|
|
|
|
The thermostat implements a PID control loop for each of the TEC channels, more details on setting up the PID control loop can be found [here](./doc/PID%20tuning.md).
|
|
|
|
## Fan control
|
|
|
|
Fan control commands are available for thermostat revisions with an integrated fan system:
|
|
1. `fan` - show fan stats: `fan_pwm`, `abs_max_tec_i`, `auto_mode`, `k_a`, `k_b`, `k_c`.
|
|
2. `fan auto` - enable auto speed controller mode, where fan speed is controlled by the fan curve `fcurve`.
|
|
3. `fan <value>` - set the fan power with the value from `1` to `100` and disable auto mode. There is no way to completely disable the fan.
|
|
Please note that power doesn't correlate with the actual speed linearly.
|
|
4. `fcurve <a> <b> <c>` - set coefficients of the controlling curve `a*x^2 + b*x + c`, where `x` is `abs_max_tec_i/MAX_TEC_I`, a normalized value in range [0,1],
|
|
i.e. the (linear) proportion of current output capacity used, on the channel with the largest current flow. The controlling curve is also clamped to [0,1].
|
|
5. `fcurve default` - restore fan curve coefficients to defaults: `a = 1.0, b = 0.0, c = 0.0`.
|