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@randomvibe, I'm not sure about the Sparkfun board, however, it seems like it should work with SPI. Refer to the pin description table on this page. I personally just got the cheapest MPU-9250 from ebay I could find. They're <$2 each when I bought them.

This has been tested on the teensy 3.0 and 3.1. Should also work for teensy 3.2.

For anyone who needs help getting the MPU-9250 working with SPI, the library with an example is here.

Thanks. I've got it working by porting this to arduino.

Has anyone gotten the MPU-9250 to work with SPI, including the magnetometer? Thanks.

Update: It seems like someone has already found the fixes, just that the main repo hasn't been updated. https://github.com/btmcmahan/Teensy-3.0-SPI-Master---Slave/pull/5 Thanks

Hi, I've been using @btmcmahan Teensy SPI master/slave library for a while (with arduino 1.0.5 and teensyduino 1.20). https://github.com/btmcmahan/Teensy-3.0-SPI-Master---Slave However, since I've needed to use the ili9341 lcd, I've updated arduino to 1.0.6 with teensyduino 1.24 to use the...

Thanks Paul. I may try that, though I'll probably end up doing some rerouting to pin 26 and removing the header of pin 33 altogether, using some messy external wiring. As a side note. I agree with ^Andre. It's probably best if this was stuck on the teensy pinout or something, or at least a...

I'm interfacing with the ili9341 with parallel, and the 10k pullup doesn't seem to work. It's wired correctly, but whenever the lcd is powered on, the voltage still drops to around 10mV. Adding anothe 680 ohm resistor in parallel with the 10k, pulls it up to around 0.500V.

Any chance of the workaround in firmware to happen soon?

Thanks guys. The pullup was just what I was thinking, just a bit ugly to solder up a pullup on a pcb. Will try soon. Moving pin assignments around will be difficult. There is only one pin left unused, that is pin 26. Perhaps for the next revision of the pcb.

Any help please? Thanks

Is the fix available yet? I'm having an issue where the device I'm using causes pin 33 to go low on power up, causing the teensy to stop working. If I connect the device after power up, everything works fine (provided I set pin 33 to output), but this is clearly not happening by default. Thanks.

Hi, Thanks! I believe the thread is now really based here. There are a few others that also are attempting a mix of software and hardware decoding at >=50kHz. Perhaps this would be of use to them. Brian

unix_guru, I suggest you try both pure software decoding or a mix of both. Right now I'm under the impression that software might just be better for encoder edge rates of <100kHz.

It's taken me a while to get the interrupts working without conflicting. I'm using a similar approach to fdavies and interestingly, using pure software decoding is faster than a mix of both hardware and software decoding. Thanks for all your help. Currently SPI slave is also working very well...

Thanks Paul. and thanks btmcmahan for the library. It works well.

Can the ibrary be used at higher speed than 24 MHZ ? Probably not. I believe it's the max (and that's very fast) On another note, Paul, is there any chance of SPI slave support on the core SPI library any time soon? thanks.

Sorry. Forgot to emphasise the built in 10k resistors (on both the breakout and the shield)

Does this library support native chip select?

I believe this is regarding the capacitive breakout? http://www.adafruit.com/product/1770 Just some tips from experience: 1. you don't really need pullups if you've only got one i2c device 2. don't rely on the irq pin. For some reason, it works very well when the screen is changing (the teensy...

Actually. Disregard this. I'm experiencing the same behavior with both now.

I've been working with the ili9341 cap touch display recently. There is an active high interrupt pin that goes low when touched. Here is a simplified version of my code: void setup(){ .... } void loop(){ while(digitalReadFast(IRQ) == HIGH); delay(1000); do{ compass()...

The PCB is expensive and quite large (the lcd is just a small part of it). They haven't arrived yet, but I'm not expecting to make another revision for a while until this one is fully tested. Furthermore, it's impossible for me to have all the 8 pins on one port (though there are suggestions to...

Unfortunately, I've made a pcb that doesn't have the right connections. The 8 pins are all split between 4 ports so I'm assuming it probably wouldn't be any faster than the method I'm using currently.

ok then. Thanks.

thanks. Perhaps I wasn't clear enough on my issue. From what I see the UTFT library uses the B and D ports of the Teensy. I am unable to connect the lcd to any of these ports, but instead have connected the pins to D0 though to D7. Is there any hope of getting it any faster?

Hi, I've spent a while modifying the Adafruit_TFTLCD library to get the ILI9341 breakout board working with the T3.1. Currently, it runs very slow (at a similar speed to the speed of the Due in this demo) This is most likely because of the way I write each byte of data. Instead of using...

Thanks TLB. fdavies, 4 20KHz encoders without hardware is impressive. Do you think it'll still work at several hundred Hz if you implemented the Teensy as an SPI slave and received commands for the target speed of each motor?

Lastly, the pins will work with 5v right?

Hi TLB, For 4x count mode, 4 counts are made per pulse (low, rising, high, falling) For 2x count mode, 2 counts are made per pulse (low, high) For 1x count mdoe, 1 count is made per pulse (just the high I believe). The encoder library is in 4x count mode...

Forgot to ask. Which type of count mode does the library support by default (I don't mind but it's good to know)?

I'm confused now, I need the cs low at all times? I have a multi-slave configuration in which I've got two teensy 3.1s as slaves, and some other spi devices.

In the new SPI library in 1.20, is it possible to change #elif defined(__arm__) && defined(TEENSYDUINO) to this? #elif defined(__arm__) && defined(CORE_TEENSY) I'm running sublime text 3 with the Stino plugin, and for some reason, TEENSYDUINO is not defined, but CORE_TEENSY is. In the...

When you say it's good to do a small delay before trying to "pop" any data received, is this on the slave? Thanks for your help.

Sorry. Worded my question wrong. Is it possible to say send 1 byte to the slave, and then receive 4 bytes from the slave (i.e. the number of bytes received is unequal to the number of bytes sent).

Hi, Regarding the SPI slave rxtx8() and rxtx16(), is it possible to send and receive data of different lengths using the current library? thanks, Brian

Thanks! I've only managed to get it compiling (by changing the things John mentioned about).

Has anyone tested this with the Teensy 3.1?

Just to confirm: Encoder X is connected to digital pins 3/4, Encoder Y is connected to digital pins 32/25? The following is from QuadDecode.h * HARDWARE DETAILS * * ENCXA 3 PTA12 28 Input FTM1 7 * ENCXB 4 PTA13 29 Input FTM1 7 * ENCYA 32 PTB18 41 Input FTM2...

I don't think the index channel is actually useful to me, as I only need velocity. thanks, Brian

One last question. I'm assuming the library doesn't support the index channel (I) from scanning through the code. Does the chip not support this? Brian

Thanks. Hopefully one of the methods will work, the preferable being the second option (third channel by direct sampling). Brian

Thanks guys. Unfortunately, having more Teensies is not really an option, as the current robot already has 4 Teensy 3.1s, each dedicated to their own specific tasks that actually require quite a lot of processing. There is no more space on the pcb for more. My experience with i2c is that it's...

Hi, I've been looking for ways to decode 3 quadrature encoders with just 1 teensy 3.1, and I've been pointed to this topic. It seems like the MK20DX256/MK20DX128 both have "Two 2-channel quadrature decoder/general purpose timers." Does this mean that the Teensy 3.1 can hardware decode two...

Thanks. Perhaps I should more clearly say what I'm trying to do. This year, I've got an 3 wheeled omnidirectional robot that runs ridiculously fast with 14W motors. There were issues with the robot not facing forwards, even with PID control with an IMU. This was contributed from two main...

Hi all, I need to be able to control the speeds (exactly) of 3 motors running at 12400rpm or 207 rotations per second. For this, I'm hoping to work with encoders that have 256 counts per revolution. That is, each motor will output 53000 counts per second. That means the teensy will need to read...