Dear community members, first of all I’d like to thank all of you for your discussions. They are of incredible value for those who follow.
Yesterday I assembled my first DIY teensy board (T3.6). After 20 hours I’m still awake, trying to understand why it fails. I read everything available on the forums.
Since MK02 chips did not arrive on time, I removed two bootloader chips from Teensies (3.2) I had lying around, carefully, with a lot of flux and hot air. Then I added one of them to my custom board.
I can measure stable 3.3v on the input of MK02, but the PROG pad seems to be floating instead of being pulled high. When I push the program button, the pad is pulled low, but when I release the button, it continues to float. It is floating in the range of 200mV.
RESET pins (PTA4, PTA13) are pulled high, and when I push the program button, they continue to stay high instead of being pulled low.
Maybe someone has had a similar problem, I would be extremely grateful for any suggestions.
1. All solder joints seem to be smooth and clean, inspected through a microscope, no offsets, no bridges;
2. 3.3v is provided nicely to both, MK66 and MK02;
3. I re-inspected schematics and layout several times in KiCad. No missing traces, no copper dirt. Everything is clean. I followed up and inspected my board with a multimeter. It corresponds to the layout;
4. Crystal is placed according to recommendations on the PJRC website;
Thanks in advance!
Follow up:
My mac sees the MK66. When I go to system report, I can see a “Kinetis Bootloader” in the USB section, but Arduino (1.8.10) sees nothing and therefore I cannot program the board.
MK02 seems to fail to respond to a “program” call and so it never sets the MK66 into programming mode.
I desoldered the MK02 chip and soldered another one, just to make sure it was not a damaged chip. The behavior is the same. RESET pad is NOT pulled high by default, which it is, on Teensy 3.2 boards I examined.
https://www.dropbox.com/s/l8tu79wkr8n338a/Screenshot%202020-03-24%20at%2016.36.42.png?dl=0
https://www.dropbox.com/s/h2tsiixsp409po8/Screenshot%202020-03-24%20at%2016.39.37.png?dl=0
Yesterday I assembled my first DIY teensy board (T3.6). After 20 hours I’m still awake, trying to understand why it fails. I read everything available on the forums.
Since MK02 chips did not arrive on time, I removed two bootloader chips from Teensies (3.2) I had lying around, carefully, with a lot of flux and hot air. Then I added one of them to my custom board.
I can measure stable 3.3v on the input of MK02, but the PROG pad seems to be floating instead of being pulled high. When I push the program button, the pad is pulled low, but when I release the button, it continues to float. It is floating in the range of 200mV.
RESET pins (PTA4, PTA13) are pulled high, and when I push the program button, they continue to stay high instead of being pulled low.
Maybe someone has had a similar problem, I would be extremely grateful for any suggestions.
1. All solder joints seem to be smooth and clean, inspected through a microscope, no offsets, no bridges;
2. 3.3v is provided nicely to both, MK66 and MK02;
3. I re-inspected schematics and layout several times in KiCad. No missing traces, no copper dirt. Everything is clean. I followed up and inspected my board with a multimeter. It corresponds to the layout;
4. Crystal is placed according to recommendations on the PJRC website;
Thanks in advance!
Follow up:
My mac sees the MK66. When I go to system report, I can see a “Kinetis Bootloader” in the USB section, but Arduino (1.8.10) sees nothing and therefore I cannot program the board.
MK02 seems to fail to respond to a “program” call and so it never sets the MK66 into programming mode.
I desoldered the MK02 chip and soldered another one, just to make sure it was not a damaged chip. The behavior is the same. RESET pad is NOT pulled high by default, which it is, on Teensy 3.2 boards I examined.
https://www.dropbox.com/s/l8tu79wkr8n338a/Screenshot%202020-03-24%20at%2016.36.42.png?dl=0
https://www.dropbox.com/s/h2tsiixsp409po8/Screenshot%202020-03-24%20at%2016.39.37.png?dl=0
Last edited: