About change U1 on the Teensy 4.1
- Thread starter Shun
- Start date
PaulStoffregen
Well-known member
At least 2 people have reported success by simply using these wide temperature range chips with fresh bootloader chips. I have not personally tested, so the best I can do is relay the feedback from people have used used these parts.
These wide temperature parts are rated for only 528 MHz, so in Arduino IDE you should select Tools > CPU Speed to be 528 MHz or less.
I can confirm the RT1062 chip runs at 396 MHz when the bootloader chip is in control, so the 528 MHz limit is not an issue for correct operation in programming mode.
These wide temperature parts are rated for only 528 MHz, so in Arduino IDE you should select Tools > CPU Speed to be 528 MHz or less.
I can confirm the RT1062 chip runs at 396 MHz when the bootloader chip is in control, so the 528 MHz limit is not an issue for correct operation in programming mode.
PaulStoffregen
Well-known member
2 questions:
Is this a custom PCB, or are you desoldering and replacing chips from a Teensy 4.1 board?
Are you pressing the Program button (or momentarily shorting the Program signal to GND) to get the board to respond?
Yes, of course the image in Teensy Loader does not match the different chip you used! This software was never designed to talk to any other hardware.
Teensy Loader shows this image (it is simple a JPEG image, not actual text) when hardware is running from the NXP ROM. Running from NXP ROM can happen even on regular unmodified Teensy 4.1 if the flash memory does not contain a valid program. Without a valid program, the processor can not boot and the NXP ROM runs instead. In that situation, simply pressing the Program button should get you into bootloader mode.
NXP ROM mode also runs if the processor is unable to boot because you do not have flash memory connected, or if there are other hardware problems. I hope you can understand how difficult it is to help in this sort of situation. Even with known good hardware, solving electronics problems over the Internet can be quite a challenge. But in a case like this, where you're replacing chips and even with circuit board you have isn't clear, almost impossible to say what's wrong. Hopefully this explanation about NXP ROM mode at least helps slightly.
Is this a custom PCB, or are you desoldering and replacing chips from a Teensy 4.1 board?
Are you pressing the Program button (or momentarily shorting the Program signal to GND) to get the board to respond?
Yes, of course the image in Teensy Loader does not match the different chip you used! This software was never designed to talk to any other hardware.
Teensy Loader shows this image (it is simple a JPEG image, not actual text) when hardware is running from the NXP ROM. Running from NXP ROM can happen even on regular unmodified Teensy 4.1 if the flash memory does not contain a valid program. Without a valid program, the processor can not boot and the NXP ROM runs instead. In that situation, simply pressing the Program button should get you into bootloader mode.
NXP ROM mode also runs if the processor is unable to boot because you do not have flash memory connected, or if there are other hardware problems. I hope you can understand how difficult it is to help in this sort of situation. Even with known good hardware, solving electronics problems over the Internet can be quite a challenge. But in a case like this, where you're replacing chips and even with circuit board you have isn't clear, almost impossible to say what's wrong. Hopefully this explanation about NXP ROM mode at least helps slightly.
PaulStoffregen
Well-known member
First to directly answer your question, you would normally just press the pushbutton to connect the Program signal to GND. Hopefully it is easy to see from the schematic that the pushbutton is connected to Program and GND.
But perhaps this does not work because your hardware changes by desoldering and soldering different chips have unintentionally damaged your Teensy 4.1 board?
Before looking for damage to parts, check whether your Teensy 4.1 is the older version which had a MKL02 bootloader chip. During the semiconductor shortages in 2022, Teensy 4.1 boards started to be manufactured with a different bootloader chip. This is documented on the Teensy 4.1 page near the schematic. The new chip has 20 pins rather than only 16, so if you were using a microscope or magnifier while soldering, you probably should have noticed the pins would not line up properly. Even after soldering, if you use a magnifier or camera with good macro zoom, you should be able to see whether the MKL02 pins line up properly with the pads on the PCB. If you have the newer Teensy 4.1 board designed for a completely different bootloader chip, then desoldering it and attempting to solder a MKL02 which does not even fit properly onto the pads obviously can not work.
But perhaps this does not work because your hardware changes by desoldering and soldering different chips have unintentionally damaged your Teensy 4.1 board?
Before looking for damage to parts, check whether your Teensy 4.1 is the older version which had a MKL02 bootloader chip. During the semiconductor shortages in 2022, Teensy 4.1 boards started to be manufactured with a different bootloader chip. This is documented on the Teensy 4.1 page near the schematic. The new chip has 20 pins rather than only 16, so if you were using a microscope or magnifier while soldering, you probably should have noticed the pins would not line up properly. Even after soldering, if you use a magnifier or camera with good macro zoom, you should be able to see whether the MKL02 pins line up properly with the pads on the PCB. If you have the newer Teensy 4.1 board designed for a completely different bootloader chip, then desoldering it and attempting to solder a MKL02 which does not even fit properly onto the pads obviously can not work.