Okay, Teensy noob here - apologies (+ sheepish shrug + sigh of relief) in advance if I'm missing something simple.
Equipment: Windows 10 desktop PC; Teensy Loader 1.52; Arduino/Teensyduino IDE, Teensy 4.0 with my pins in either 1) sockets on a solderless breadboard or 2) sockets on my carrier board. Teensy USB connection IS to a USB hub because I'm squeamish about frying USB's in my desktop PC.
FWIW, I'm trying to build a maximum power point tracking charge controller for solar cells and a lithium ion battery. So I got my proto circuit board back from fab, stuffed it with components, and did some preliminary testing before socketing the Teensy 4.0. The power on my proto circuit board currently (batteries later) first comes from a loosely regulated wall wart transformer, then to a 1.5A, 5VDC linear regulator, then to a ~750mA, 3.3 VDC linear regulator. The extra 3V3 regulator is if I want to add power-hungry devices to my I2C bus later. (Refer to the schematic for power details)
Note that my early testing has been done without solar power input, presence of a battery, or presence of any load. I'm just trying to wake this board up.
The schematic shows the voltages that I read from various parts of the circuit. My problem is that when I have cut the jumper between VIN and VUSB and mount the board in the sockets on my carrier board, Teensy Loader does not recognize the attached (through the on-board USB connector) Teensy 4.0.
I've gone so far as to only power the Teensy board itself with my "5 VDC" (4.67 VDC) source to the VIN pin (no other pins connected to anything) and plug the USB cable in and yet my PC and Teensy Loader still do not recognize the board.
I tried the hold-the-button-down-for-15-seconds-trick, got a single blink of the red LED a little after 12 seconds, but no apparent reload and run of the slow blink code. And definitely no recognition of the board from Teensy Loader.
But after I made a solder bridge re-connecting VIN and VUSB, (powered by USB; no Vin connection to my 5 VDC) the Teensy 4.0 is happy again, loading sketches, responding the the 15-second reset, talking to an I2C device I have hooked up; talking via USB serial to PuTTY, giving me status, etc. And without a PC reboot.
So what have I done to foul up the USB (?) communication of the Teensy 4.0 board with my computer by cutting the Vin/VUSB jumper and powering the board from the non-USB source? And how was the fault not permanent?
The Teensy board seems to be 6-layers (?) and I'm pretty sure I didn't get so heavy handed that I cut through buried circuitry, but I'm not ruling that out.
Any and all help will be much appreciated.
Equipment: Windows 10 desktop PC; Teensy Loader 1.52; Arduino/Teensyduino IDE, Teensy 4.0 with my pins in either 1) sockets on a solderless breadboard or 2) sockets on my carrier board. Teensy USB connection IS to a USB hub because I'm squeamish about frying USB's in my desktop PC.
FWIW, I'm trying to build a maximum power point tracking charge controller for solar cells and a lithium ion battery. So I got my proto circuit board back from fab, stuffed it with components, and did some preliminary testing before socketing the Teensy 4.0. The power on my proto circuit board currently (batteries later) first comes from a loosely regulated wall wart transformer, then to a 1.5A, 5VDC linear regulator, then to a ~750mA, 3.3 VDC linear regulator. The extra 3V3 regulator is if I want to add power-hungry devices to my I2C bus later. (Refer to the schematic for power details)
Note that my early testing has been done without solar power input, presence of a battery, or presence of any load. I'm just trying to wake this board up.
The schematic shows the voltages that I read from various parts of the circuit. My problem is that when I have cut the jumper between VIN and VUSB and mount the board in the sockets on my carrier board, Teensy Loader does not recognize the attached (through the on-board USB connector) Teensy 4.0.
I've gone so far as to only power the Teensy board itself with my "5 VDC" (4.67 VDC) source to the VIN pin (no other pins connected to anything) and plug the USB cable in and yet my PC and Teensy Loader still do not recognize the board.
I tried the hold-the-button-down-for-15-seconds-trick, got a single blink of the red LED a little after 12 seconds, but no apparent reload and run of the slow blink code. And definitely no recognition of the board from Teensy Loader.
But after I made a solder bridge re-connecting VIN and VUSB, (powered by USB; no Vin connection to my 5 VDC) the Teensy 4.0 is happy again, loading sketches, responding the the 15-second reset, talking to an I2C device I have hooked up; talking via USB serial to PuTTY, giving me status, etc. And without a PC reboot.
So what have I done to foul up the USB (?) communication of the Teensy 4.0 board with my computer by cutting the Vin/VUSB jumper and powering the board from the non-USB source? And how was the fault not permanent?
The Teensy board seems to be 6-layers (?) and I'm pretty sure I didn't get so heavy handed that I cut through buried circuitry, but I'm not ruling that out.
Any and all help will be much appreciated.