Hello,
I recently purchased 2pcs Teensy 3.2 from Mouser, 474-DEV-13736 reportedly from SparkFun.
When connecting one of them for the first time I noticed the lack of the typical "device connected sound" present on Windows machines, but thought little of it.
Tried downloading code and it didn't work until I pressed the PROG button, which was also unusual.
I've worked with hundreds of Teensy 3.2 and never had a problem (with a fresh one), but I've also never bought a Teensy that didn't come from PRJC.
What happens is that there is about a 50/50 chance the processor boots up or not.
When it does not, the firmware does not launch and the computer does not recognize anything being connected, as it still would if there had been an infinite loop in setup for example.
Pressing the PROG button works fine and as soon as the new firmware is written it launches without issue.
The problem never re-occurs until the Teensy is powered down and up again and the behavior is the same when powered from the VIN rail (3V3 not tested).
This behavior happens regardless of what program is loaded (e.g. "blink" behaves exactly the same way).
"Normalclocking" the processor at 72MHz has no effect.
Quite stupidly, I've already assembled this into a product and replacing it would be quite a bit of effort, so I was hoping that someone could offer some insight into what may be going and and possibly suggest a way to work around the issue.
Best,
stg
I recently purchased 2pcs Teensy 3.2 from Mouser, 474-DEV-13736 reportedly from SparkFun.
When connecting one of them for the first time I noticed the lack of the typical "device connected sound" present on Windows machines, but thought little of it.
Tried downloading code and it didn't work until I pressed the PROG button, which was also unusual.
I've worked with hundreds of Teensy 3.2 and never had a problem (with a fresh one), but I've also never bought a Teensy that didn't come from PRJC.
What happens is that there is about a 50/50 chance the processor boots up or not.
When it does not, the firmware does not launch and the computer does not recognize anything being connected, as it still would if there had been an infinite loop in setup for example.
Pressing the PROG button works fine and as soon as the new firmware is written it launches without issue.
The problem never re-occurs until the Teensy is powered down and up again and the behavior is the same when powered from the VIN rail (3V3 not tested).
This behavior happens regardless of what program is loaded (e.g. "blink" behaves exactly the same way).
"Normalclocking" the processor at 72MHz has no effect.
Quite stupidly, I've already assembled this into a product and replacing it would be quite a bit of effort, so I was hoping that someone could offer some insight into what may be going and and possibly suggest a way to work around the issue.
Best,
stg