Select nodes had this flag enabled, testing by the community
and hardware specs indicate this can be enabled global for all
node types using this chipset.
Any nodes down the line that may be quirky can be individually
disabled with `-U USE_CC310_HW_CRYPTO`.
After soaking for a bit on the adverts without issue on multiple nodes,
I added more hardware crypto.
Supported nodes is unchanged in this PR addition, but if others can verify,
they can easily be added.
Some info on the CC310: https://docs.nordicsemi.com/r/bundle/ps_nrf9151/page/cryptocell.html
**Added:**
- AES-128 packet encryption/decryption now use hardware crypto
- HMAC-SHA-256 authentication now uses hardware crypto
- ACK hash computation and channel ID derivation now use hardware crypto
- RNG (random number generator) now uses hardware crypto rather than
radio noise + weak software RNG (which can have issues if there's
no surrounding radio noise.) NIST SP 800-90B certified.
- Runs hardware self-tests on startup
- Runs continuous health tests during operation
- Uses thermal noise/shot noise for randomness
**Unchanged:**
- calcSharedSecret remains software - it would be a split hw/sw solution
and added complexity for likely not a lot of gains. This only happens
when establishing a new contact, so not too frequent to be worth it.
- ed25519_create_keypair remains software. This is only called when a
node is first initialized. It does use the hardware RNG change, however,
so better randomization.
Tested on (so far):
- Heltec t096
Build test on:
- Heltec t096 companion ble
- t1000e companion ble
- RAK 4631 repeater
- RAK 3401 companion BLE
- Heltec v3 companion wifi
While working on some sensor code implementations, I ran into
some hard crashes that root-caused to the 4KB loop task stack
being exhausted.
Looking for various optimization schemes resulted in this relatively
low-lift fix. RAK3401 and RAK4631 both support hardware crypto.
Rather than loading in one of the two software crypto libs,
we can just use the onboard hardware. This is faster, should
consume less power, and in testing used a scant up to 700
bytes in the run loop vs 2.5-3KB per advert.
This change **only** affects advert verification processing, which
currently consumes a significant chunk of the 4KB run loop.
I figured such a change should likely be implemented in phases.
After soaking, this hardware crypto verification
process could be implemented across the entire MeshCore
cryptographic function on RAK nodes. Also possible other nodes
have available hardware crypto, however, I have not checked,
so future improvements may also exist there.
Tested on:
- RAK3401 RAK 1W
- RAK4631 19001
This is a consolidation of my changes for BME680 on RAK4631 nodes.
I will close my other PRs related to this and link back to this one.
*Background on change:*
This change replaces the Adafruit BME680 driver on RAK4631 with the
Bosch BSEC library. Other boards continue to use the existing
Adafruit path via ENV_INCLUDE_BME680.
This makes the IAQ portion of the sensor functional, and more accurate.
It also contains the math and/or CayenneLPP fixes from my other PRs.
The Bosch code also appears to handle calibrating sensor aging as well,
whereas the Adafruit code is just looking at blind values that can drift
with time. Pretty cool to see this shooting out useful data!
RAK4631 platform.io is set to override to ENV_INCLUDE_BME680_BSEC while
leaving the Adafruit code for other node types. (If this becomes applicable
for other node types in future, awesome! I just don't have hardware
to test against.)
Using the BSEC library introduces IAQ sensor calibration, and saves
the calibration state periodically so it does not have to calibrate
again later.
At startup the IAQ sensor takes 30 minutes to heat and to hit a baseline,
then starts calibrating. Once calibrated, it will save those settings
and will only write settings again if calibration falls back and restores
back to state 3.
This fix also has the gas resistance math fix that was in
[pull 2146](https://github.com/meshcore-dev/MeshCore/pull/2146) so
the adafruit path also can at least show accurate values instead
of looping negative.
Also includes the fix from [pull 2149](https://github.com/meshcore-dev/MeshCore/pull/2149) so the pressure output isn't truncated to 1hPa steps.
*Fixes/Changes:*
- Add bsec_config_iaq[] with the 3.3V/3s-LP/28d calibration profile
- BSEC init applies setConfig() for voltage-correct heater targeting
- IAQ, heat-compensated temperature/humidity, pressure, and altitude
reported over CayenneLPP
- IAQ accuracy reported as analog input over CayenneLPP (0,1,2,3)
- Calibration state persisted to /bsec_state.bin on nRF52 internal
flash; written only when iaqAccuracy improves to >= 2, should
keep write frequency well within flash endurance over device lifetime
- Fix non-BSEC query_bme680: float pressure division, addGenericSensor
for gas resistance (was addAnalogInput, overflows at > 327 Ohm)
- loop() correctly gated for both GPS and BSEC-only builds
- Add fix_bsec_lib.py extra_script to resolve nRF52840 hard-float ABI
mismatch in Bosch's PlatformIO packaging, silly Bosch
One general note outside of this code change: I noticed while BME680
_functions_ in companion nodes, since companion nodes run Bluetooth,
BLE preempts the CPU, and can do so mid-I2C-transaction.
This can cause the BME680 to see an anomaly and drop calibration and
start a recalibrate. This is behavior that will exist (and has existed)
regardless of using the Adafruit or Bosch paths.
This particular companion behavior does not seem to occur in sensor
or repeater nodes since their BLE is off. Probably affects other
I2C devices as well.
*Tests:*
- RAK19003
- RAK19007
- RAK19001
- repeater, sensor, companion
This is a medium-ish refactor to attempt to clean up sensor handling logic both for board stability and future potential growth before the code becomes all spaghetti and meatballs.
I'd be curious to see if anyone running sensors out there that knows how to build and flash MeshCore code could give this a try and see how it behaves. It is working fine on my end on multiple nodes.
PR notes are gigantic because it is a fundamental behavior repair for sensors, so I wanted to over-explain. Also, if it hadn't been mentioned previously, push-back is always welcome. I'm just spending my time trying to clean up / fix / enhance this corner of the firmware, and want to contribute my improvements back to the project.
**Problem:**
Current MeshCore code makes no attempt to see what sensors are actually available on the I2C bus at startup and blindly tries to interact with sensors. This has some very bad side-effects, like if a sensor that is unsupported, or has a weird initialization process, the MeshCore node will just hang at boot and never successfully start up and ostensibly looks bricked, or the INA226 and SHT4X both sharing the same address and the code just silently fighting.
The current implementation also gloms sensor readouts from the MCU and environment sensors onto the same telemetry channel, with some arbitrary exceptions for incrementing channels based on certain behavioral situations. The MCU temperature and external temperature sensors would appear on channel 1, and it wouldn't be possible to tell which sensor the temperature value was coming from.
Per [CayenneLPP](https://github.com/myDevicesIoT/CayenneLPP): *Data Channel: Uniquely identifies each sensor in the device across frames, eg. “indoor sensor”* So this channel division implementation falls inline with what CayenneLPP intended. There are up to 256 channels available. So I tried to model this change in that behavioral style.
**Proposed Improvement:**
This implementation scans the I2C bus for what devices are present, sets each sensor to its own CayenneLPP channel, and keeps MCU telemetry on channel 1 only. So Channel 1 is always "self" and no confusion can result.
Details:
- Channel 1 is always the MCU and things about it, so you always know that telemetry is from the board itself. Exception is GPS, GPS stays on channel 1 as well since it is "about the board" even though it's a bit gray-area as GPS can often be a secondary chip.
- Each sensor board is allocated to a dedicated CayenneLPP channel, so if you are reading from that channel, you know the data is from that sensor only. (Sensors emitting more than one of the same type of measurement are exceptions.)
- `scanI2CBus()` probes addresses 0x08–0x77 with raw `beginTransmission`/`endTransmission`. No sensor library is touched until after this completes. This will prevent sensor-based boot hangs, unknown or unresponsive devices never reach a library init call.
- Created `SENSOR_TABLE` a compile-time array that is gated by the existing `ENV_INCLUDE_*` macros. A sentinel `{ 0, nullptr, nullptr, nullptr }` at the end keeps the array non-empty regardless of which sensors are enabled, avoiding zero-length array warnings.
- When `begin()` is called, scan first, then loop: skip if address not detected, skip if `init()` returns 0, otherwise register one ActiveSensor entry per sub-channel.
- `querySensors()` I replaced the entire #ifdef chain with a 3-line loop.
- T1000-E has its own T1000SensorManager, so it should be completely unaffected by this change.
- SHT4X quirky initialization behavior is retained.
- MLX90614 - git commits around this didn't have any notes as to why it is reporting ambient temperature on a separate channel as well as the object temperature, as the ambient temperature is used internally to compute the object temperature and not really needed for the sensor's purpose - just the same, kept the existing behavior of reporting the ambient temperature one channel above the channel assigned to the sensor
- All `bool *_initialized` fields are gone, replaced with `ActiveSensor _active_sensors[16]` (query function pointer and sub-channel index) and `_active_sensor_count. SensorDef` lives entirely in the `.cpp` so the header has no dependency on it.
- Details on the INA226 and SHT4X: both default to address 0x44, the old code had a bug and would have both begin() calls fire and they would just fight each other silently. In the new code, the respective sensor code is only called if the device is actually present, however, if both were present simultaneously, SHT4X comes first in the table and would win, and INA226 would return false and be skipped. The INA226 has 16 possible addresses that are configurable in the hardware itself, so in a potential scenario where both sensors would be present, the person implementing that design could take that into account.
- BME680 gas resistance will now transmit on the same channel as the rest of BME680 telemetry which is inline with CayenneLPP standards. Coupling this PR with https://github.com/meshcore-dev/MeshCore/pull/2146 streamline the whole sensor telemetry, and with https://github.com/meshcore-dev/MeshCore/pull/2149 will overall improve BME680 handling. The gas resistance sensor actually has a binary library to make it more useful, calibration, accounting for age of sensor, and other improvements, but since that adds more flash consumption, I have omitted that in PRs thus far.
- RAK12035 and other current upstream dev branch changes integrated.
Nick Dunklee