Bus Fault - Notecard

Hardware
1

I have a NOTE-WBNAN used in a custom design that has been having network connection difficulties. Recently I switched from Periodic Mode to Continuous Mode using a firmware update and after a day and a half the Notecard reported a bus fault through health.qo

“body”: {
“text”: “boot (bus fault & [PC:134283076] [16689] [4.0] G:Gp:W~ M:Mp:W900 U:W0 R:Rp:W~ S:Spon:DONos3:ping:XRxte T I:H)”,
“voltage”: 4.7617188
}

The Notecard went offline for about 5 hours then returned to the network. The host MCU operated during this time based on feedback from the customer that our Status LED was active.

Does anyone have insight into diagnosing the bus fault code?

2

Hi @zfields @RobLauer, I am looking for someone who might be able to help or point me in the direction of documentation for this. Thanks!

4

I asked around the office and I’ve got an answer of sorts…

First, a bus fault is completely unexpected behavior (it should never happen under any circumstance), and we hardly, if ever, see them.

Based on the message you’ve provided, the Notecard’s MCU was in the middle of transmitting something to the modem when the bus fault occurred.

When this happens in isolation, we tend to believe it is a one-off occurrence. If this were to happen repeatedly, it is indicative of a hardware issue and warrants deeper analysis.

~Zak

5

Thanks @zfields, I’ve seen this occur in a second device recently as well which prompted me to circle back to the discussion. When you say indicative of a hardware issue, do you mean Notecard hardware issue or a hardware issue that is external to the Notecard? IE in this case, it would be a custom board and power supply that serve the Notecard.