| Electronics > Repair |
| Replacing a nRF8001 radio in a Wahoo Kickr indoor Cycle trainer |
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| erikbrenn:
Hi, I'm trying to fix a sensor board for a Wahoo Kickr cycle trainer. The sensor board has various inputs common on a cycle trainer, like rotary encoder (ir) for speed measurements, wattage sensor, etc. On the board there are two Nordic radios for communication with phone/pc, one NRF8001 for BLE and one NRF24AP2 with an ANT protocol stack. In addition there is a MSP uController and a couple of smaller chips I haven't been able to identify. Problem My phone is able to detect the trainer and pair with it, which indicates that the BLE comms are somewhat ok. But the trainer does not acknowledge any instructions from me/my phone when I set the wattage. I have testet the sensorboard on another working trainer, same problem, hence it must be this sensor board. And since I'm not really using the ANT features I recon the bluetooth comms are broken. However, if I push hard on the pedals the radio comms seem to work, at least the app then shows some wattage, which I assume it receives from the trainer. Altough I don't know if it's correct value. Visual inspection of boards shows now damage. Measured all caps and no shorts. I have also taken diode measurements of all test points and compared with a board from working trainer, they're all ok. There are no replacement boards to be found for this rather expensive equipment. I want to try to replace the Nordic radios, they are quite cheap. But according to datasheet https://docs.rs-online.com/7e86/0900766b81429d60.pdf these chips have both common RAM and NVRAM to hold configuration for oscillator setup etc. And unfortunately the NVRAM is write-once only! What are your thoughts on this? If configuration is stored in NVRAM, is there any way of reading it in order to program a new chip? Is it likely that the radios are configured on-the-fly by the micro during startup? Probably not... I was considering ordering a couple of NRF8001 chips to test a drop-in replacement. Perhaps also a devkit if its possible to read the NVRAM .... Cheers, Erik ps: in case you wonder about a couple of resistors that looks out of placement near the radios, they're like that from factory, |
| thm_w:
So it can pair with bluetooth, it can read data back, it can take watt settings but does not apply them. Wouldn't this indicate there is something up with whatever output it is using to set the wattage/resistance level? Are there any other commands you can send that set parameters, that would tell you that writing data is or is not working? |
| erikbrenn:
Thanks a lot for input! Good point. There are two connectors on the board, a 4-pin and a larger white connector, of which several pins are NC. Both cables go down the "body" of the trainer as shown in pic below. The wire I'm holding has a infrared sensor in the end, which reads the encoded wheel you see on the trainer side. Assuming that you are right, and that the 4-wire connection seen in the photo connects to the "wattage controller" board down/inside the flywheel, I might try to replace the two chips that seems to interface the microcontroller to this connector. However I have not been able to identify them. One is marked "DACL 1230 SVS", while the other is a TI chip marked 1333A or I333A Here is a closeup: Any ideas what they could be? |
| up8051:
I333A = TI INA333A |
| cozza:
Have you checked the optical encoder is working properly? When faultfinding stuff like this, it pays to check the things which are likely to fail, the nordic radio chipsets are not really in this category unless ESD / or a regulator fails. A bad or low emission led in one of these arrangements wouldn't be unheard of. Look at the LED with a phone camera, and check the photo transistor output with a scope for good clean switching on each black white transition. (you may need to shield ambient light from it) If it pairs on BT and takes a wattage setting but doesn't apply it, the first thing to check would be all the feedback inputs to the controller first. |
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