Is it fried? No TCXO

MMDVM_HS Hat hardware
Post Reply
KN4IJP
Posts: 7
Joined: Mon Jul 01, 2019 2:02 pm

Is it fried? No TCXO

Post by KN4IJP »

History- built my first hotspot on 7/3 with pi Zero and eBay MMDVM board. Followed directions by Toshen to a T and only enabled DStar. Setup home WIFI and iPhone hotspot.

Everything worked perfectly! Made several contacts from home WIFI on 7/3 and 7/4. Zero loss and 0% BER.

Then on 7/5 I took everything to work. Monitored DStar all day and made a couple contacts via iPhone hotspot. CPU temps were around 100-110 degrees.

After work I wanted to try mobile. Started Jeep, plugged iPhone into USB for power (that was connected to Car Play), turned on iPhone hotspot. Then I set Jumbospot in dash tray, activated OEM Jeep converter and plugged my Jumbospot into the 110v socket.

Jumbospot got really hot to the touch. Couldn’t connect with radio when keying up. Seemed like Jumbospot shutdown due to overheating. I realized that I had inadvertently set the Jumbospot on top of a large metal coin that was in the dash tray. My Jumbospot isn’t in a case yet. I wondered if I shorted something out?

When I got home I reconnect and noticed dashboard was showing everything in green except DStar on Modes Enabled. Also the CPU was up to about 150 degrees. I did a lot of forum and internet searching to diagnose it. The good news is I’ve learned a lot!

So...I completely reformatted the SD card, flashed Pi-Star again and setup everything from the beginning. DStar mode still red. CPU still hot. Started digging around in SSH (new to me). Ran update in SSH. Them tried to flash MMDVM firmware a couple times. Got a “failed to init device” error. It’s also mentioning something about Arduino.

Ran logs during reboot and get the failed to (something...) after six tries message.

What else can I try? What did I do wrong? Time for a new board?

Image



Sent from my iPhone using Tapatalk
KN4IJP
Posts: 7
Joined: Mon Jul 01, 2019 2:02 pm

Re: Is it fried? No TCXO

Post by KN4IJP »

Thanks for the feedback! I appreciate your help.

So I pressed the reset button on the MMDVM. After it reset I tried to flash the firmware again. No changes.

I removed the MMDVM board and restarted the Pi. Seemed hotter without the MMDVM.

Turned off power to Pi via Pi-Star. Waited 10-15 minutes. Pi was still pretty hot just being plugged into electricity even though it wasn’t powered on.

Restarted just the Pi without MMDVM. By the time it connected to WIFI show I could check Admin it showed 142 degrees.

Looks like the Pi was damaged? I’m wondering if the MMDVM was damaged as well? I don’t have another Pi or MMDVM board for additional testing. Going on an RV road trip in 2 weeks and wanted to use the hotspot. I hate to buy everything again if the MMDVM board is ok. Any way to test it through commands or logs?


Sent from my iPhone using Tapatalk
KN4IJP
Posts: 7
Joined: Mon Jul 01, 2019 2:02 pm

Re: Is it fried? No TCXO

Post by KN4IJP »

Thanks for the tips. It looks like the Pi serial port may be bad.

All the lights on the MMDVM flash as normal on startup. Then the green light stays solid while the red service light blinks. Seems like that’s how it was before it broke.

A search for the MMDVM log shows “unable to read firmware version after six attempts” before and after a firmware flash holding down the button on the boot board. Also still getting the failed to init message after firmware flash.

Tried to test the serial port with minicom using sudo minicom -D /dev/ttyS0. Also tried sudo minicom -D /dev/tty8. Both with pins 8 and 10 connected. It shows Welcome to minicom message for both ports but doesn’t display any typing after that.

I think I’ll order a new Pi and maybe a new MMDVM.


Sent from my iPhone using Tapatalk
KN4IJP
Posts: 7
Joined: Mon Jul 01, 2019 2:02 pm

Re: Is it fried? No TCXO

Post by KN4IJP »

KE7FNS wrote: Don't forget a case too.
Haha; that’s awesome! The case just came today. Ordered it right before I fried the hotspot.

I’ll give these next steps a try tonight. The board is a generic Chinese board off eBay. The button on the board is a reset. I haven’t been able to find the directions to put it in flash mode yet.

ImageImage



Sent from my iPhone using Tapatalk
KN4IJP
Posts: 7
Joined: Mon Jul 01, 2019 2:02 pm

Re: Is it fried? No TCXO

Post by KN4IJP »

I got it working. Looks like it was the serial port of the raspberry pi. Bought a new Pi.

In the case! Thanks for all your help!

Image


Sent from my iPhone using Tapatalk
Post Reply