Hi Kurt,
I’m driving the lcd at the moment via 8/16bit 8080 on GPIO6 writing directly to the port.
It works quite fast but I am afraid that when I start to add more functions and interrupts its going to impact that...
The RingBuf class can be used in an ISR. I did a ping-pong ADC DMA test with Teensy 3.6 over-clocking the ADC and am able to log 6MB/sec.
Here is a link to that demo.
...
I have an example using SdFat for USB mass storage with a Mega ADK. I once posted "UsbFat" on github but found almost no interest. I think it was too early and the ADK was never popular.
Unfortunately the source buffer comes from the Print class and the destination buffer alignment depends on how many bytes have been written to the file.
I tested the above on a demo of a data logger that uses mods I...
Are you sure it's really a 4.7K resistor?
When we've seen problems like this before, with intermittent communication having CRC errors, the cause was a much higher resistor value mistakenly used instead of 4.7K.
...
There is another possible solution. SdFat keeps an index that is used to update the directory entry. This can be used to open files.
Long ago I wrote an example using open by index to test the idea. I just tried...
### Description
I have problems to connect to a DS18B20 temperature sensor when using the example DS18x20.
When the sketch is loaded into the module "No more addresses" is printed repeatedly, see below.
However,...
The interesting thing is I tried the simple version that crashed after 3 plus seconds to Flash to go instead to SDIO. Again 512 bytes at a time.
CMD: 100c(SEND_OBJECT_INFO)l: 20 T:299 : 1 ffffffff...
XBAR - for me it was reading the manual a few times.. (sometimes more than a few)... Note: So far when playing with DMA, I have mainly needed to have some understanding of XBAR for GPIO and for ADC... Note: ADC is a...
I am trying to understand the flash writing code I found in the EEPROM emulation (https://github.com/PaulStoffregen/cores/blob/master/teensy4/eeprom.c) and the flasher4 OTA code.
A lot is going on to set up the...
@miciwan great post! Do you have any reference to information about XBAR besides the technical manual?
What other methods are there to trigger a DMA transfer? And how would one attach a clock signal to a DMA transfer...
Yes. Your explanation makes sense and now I know why such a method does not and will not exist in the SD library. That said then, it appears my original calloc(), recalloc() method of placing each filename in an array...
This seems to work. It is efficient except at the 0X20000000 boundary.
// Tensy3 memcpy
inline bool is_aligned(const void* ptr, uintptr_t alignment) {
auto iptr = reinterpret_cast<uintptr_t>(ptr);
return...
You'll definitely need those resistors (I2C pull-ups, RESET, REXT), so see if you can get them soldered in somehow.
And looking at the schematic, it seems you are using 5v+ for some of the devices, including the...
Hi All
I didn't realise that the Teensy 4.1 had a MAC address burned into its eFUSEs until reading this thread so I read out the eFUSEs on my board:
eFUSEs
======
LOCK
0x40528107
CFG
0x677f0555
I working on this some more and looking into the code compiled I see this about middle of the code (about 129k total code size)
:10FFE000704700BF18EA0100054A02608A7D02716D.....
In that case I might be better and cheaper off to order the audio shield. I wanted to save some money by using the class D I already have and maybe learn something about audio op amps on the way.
I used PSpice...
@Frank, no problem! Best regards from Esslingen. I just was not too happy, because I think the idea is not completely silly and because it takes some time for me to write - especially in English.
@Paul: This forth...
No doubt there are some users who are able to "insert the SD card I mailed you" and not "install this software on your PC and then ....". You can start with "Flasher4" if you want to develop software to do this.
Yes it would be very handy to have SDRAM option on board. Note that this Daisy board uses STM32H750 microcontroller at @480MHz so it is already significantly slower than existing Teensy 4 @600MHz, and nowhere near to...
I have written a ring buffer class for buffering data during SD busy time. It works well if I use it for buffering full sectors. I have declared the buffer array like this. Size is a multiple of 512 bytes so everything...
Morning @KurtE
Know what you mean. Last night was playing your send_object_large branch and playing around with buffer sizes. Unfortunately couldn't get it to work with NANDs for large files. Transfers would time...
Totally understand.... Pretty frustrating.
This morning I decided to waste some time and see if going at this completely wrong. So tried a KISS version of the code...
bool MTPD::SendObject() {
bool...
what is slow? reception? transmission? code responses? how does the loop() code look like? are you using events()? if using events(), there may be a delay somewhere in your code before the queue can be read, if so try...
Could you tell me what driver strength mods you think would work and I will include them in my tests. I have a number of Tennsy 4.1 and 3.6 boards running tests on my new Teensy driver mods.
I am in the process of...
The problem with scanning a directory backwards is that a file has an variable number 32 byte entries and they are designed to be scanned in the forward direction. For example in exFAT the set count is in the first...
You can have up to 8 FIFO filters (0-7) by default, 8 more after sacrificing 2 mailboxes (0-15), which would leave you with 6 TX mailboxes instead of default 8. It's a bit complex but highly customizable. FIFO has 6...
Hi
The connector on the socket may be 180° reversed. Like this the LED won't work since its polarity is incorrect but the Ethernet still works (as I have heard) since it doesn't care about the line's polarity...
Thank you tonton81.
Instead of using setMBFilter(MB7, 0x18DAF111, EXT), but I try to use setFIFOFilter(0, 0x18DAF111,EXT).
Things are going forward and nicer.
if you enable FIFO, you dont have any reception mailboxes, only 8 TX mailboxes MB8-MB15. Because you are using FIFO without mailboxes you should use setFIFOFilter(0, 0x18DAF111,EXT)... 0 for 1st fifo filter.
MB99 is...
I'm afraid currently there is no good solution for more than 16MB RAM.
One could come up with the idea of simply using multiple (more than 2) PSRAMs on QSPI. But that's difficult because they would need multiple...
Thank you tonton81!
anyway, with the following source code, Teensy4.0 can talk with my Honda FIT 2012 model year.
I have to enable FIFO and change MB1 to MB7. I did not check MB4 through MB7.
As you can see the...
i2sflew: I highly recommend that you get used to typing your circuits into LTSpice. You can even add noise to the power supply or input. Not perfect, but you will learn a lot.
In many cases like this, it is often easiest to look at code that ships with the Teensyduino release, at least to get ideas, even if you may be the type who who wants to write everything from scratch.
In this case...
I tried to come along with a solution, but haven't find one. The strange thing about it is, that the socket on the Teensy doesn't light up in any way, but the socket on the laptop lights red...
But ping still works....
Not possible. Many of the required signals are not accessible.
But you can add QSPI PSRAM.
https://www.pjrc.com/store/psram.html
The raw performance for cache misses is obviously lower for 4 bit QSPI compared...
I'd like to see usb-c and some ~64mb sdram on the next teensy. There is a competitor called daisy which has 64mb sdram onboard. But the teensy might again feature ethernet and definitely features more solid libraries...
Hi,
I've checked in the datasheet of the 1060 that it has an external memory interface for sdram. So I'm thinking and research how hard it would be to hook up some sdram (around 64MB) to the teensy or if it isn't...
Nice write up - Puts a lot of the details into one place which is great.
Note: another gotcha you may run into with DMA is with caching.
That is with the example above you are using the dmabuffer
DMAChannel...
I'd say should use, not must use :)
For low voltage circuitry many old style opamps are bad news as they require dual rail supplies - a modern
true rail-to-rail audio spec'd opamp is a better choice as only a 5V...
I'll try adding it back into Win10 Meinberg NTP ntp.conf and see what happens. It may have been just a coincidence that it "got happy" right after I removed it (and restarted the service with services.msc).
...
Well, yes. You might guess that from "Posts" count. In fact Frank has a long history of contributing not just good ideas, and a lot of pretty amazing code. So his voice & opinion does carry quite a bit of weight...
Absolutely not, you'll be driving them into slew-rating limiting which is massively distorting (the feedback loop
completely loses lock). Also the step change in input may destroy the front-end of an audio opamp,...
I've created a very low-noise Teensy Audio Shield so I can assure you it can be done. Take a look here for full details, including the schematic: TGA Pro
For starters with PJRC Audio Board, you must turn off the HPF...
Right! NEED * MORE * COFFEE and tried to edit Post #3. I wasnt aware that this options runs out after some Time???
Most recent (branded) PSUs work just fine, only the cheapest ones (hence the ones with older...
This is my 2 legged Robot project built with a Teensy 4.1 and using Unity and 6 Odrive with 12 brushless motors 56v
This is only my first attempt I have a new design on the way.
If you have any questions I will be...
Inductance is measured in henries, not farads... 33µH perhaps?
If you drive audio amp from a switch-mode supply (not recommended), then make sure its one with an
ultrasonic switching frequency (and beware the sort...
TEENSY 4.1 CAN bus question about speed?
The CAN bus is working perfectly except it seems to only update every 0.5 seconds and I dont know why :( You can see in the code that I have the BaudRate set to 1000000 so I...
Thank's you very much for your fast answer.It's works nice.
This thing seems very noisy, maybe PWM is more sensitive to it instead of SPI/I2C.
But it could be a good opportunity to see the impact using a shielded...
You need to test any driver mod with files of at least 8 GiB on the popular SD cards from Samsung, Sandisk and the new Kingston Canvas Plus. I also test on older cards. You need to use a variety of write patterns...
You can add this functionality to your program.
Thats even better than to have it in the PJRC-bootloader (and other people may not want it)
You just have to make sure, that this part is íncluded to the program on SD,...
Thank you both for the explanations.
The idea was: To ship the T4.1 with the SD-Bootloader already flashed to every customer.
For myself I can flash the Teensy and I can load an application written in Forth from...
First glance it should be easier on the 1062 with external flash? As long as all needed code for the Flash writes is RAM resident - which user code is by default. But again that is not how the Teensy bootloader or the...
As noted in p#6 - Frank personally wrote such a 'code from SD' - so that was based on experience doing that and a great understanding of the Teensy programming process, not a coin toss - or anything that should be taken...
Oh, I think it's not too difficult to write some code that loads a program from SD to RAM and executes it there. Might involve reserving some space in ITCM (via .ld file), some stack tricks, fiddling with the...
Well, Frank, you answered negative within 4 Minutes to my idea, saying that there is no need for it, this felt to me like "crushed down". Have you been part of a group doing brainstorming in the past? There is an...
Not seen this come up before - but did find this app note for a different freescale/NXP processor : nxp.com/docs/en/application-note/AN5245.pdf
If the 1062 can support it as desired those notes may help - or suggest...
not crushed, i.e. discarded without reason - just noting a few hurdles making it non-trivial. One of which is the bootloader has one function and limited connectivity only to processor and none to SD card - it can "on...
Hello,
Could you help me if you have a solution?
My problem is that I cannot write values to LPI2C registers.
1. I can read LPI2C1_VERID and LPI2C1_PARAM.
2. I tried to write 0x00000001 to LPI2C1_MCR,...
Did not "crush it down". Just said that I think that it is not really needed. There are TODOs with much higher priority.
Can Raspi do what Teensy can? :) Work without SD? :) Boot in a few milliseconds?
That's a...
Start the Teensyloader. - Up to now I have installed Arduino first and then Teensy with all its compiler and libraries. Ok, I found now, that there is indeed a "Loader-Only-Installation." Good to know, because the idea...
Tested to work - Using a T_4.0 with loglow/TallDog T_4.0 board PCB to present SDIO pins to an SD socket.
That does not have PSRAM - but with reduced BUFFER it will use processor memory instead when EXTRAM is...
Indeed - even if that were a supported way to upload - where today it only via USB upload - it would take some orchestration overhead to ONLY do it once and not reProgram every time if the SD card were not removed.
...
Moin Ben!
First, you have t understand that you NEVER should run Audio Circuits directly from a non trustworhty, possibly unstabilized and unfiltered rail, especially if you have a common GND with some digital...
Hi,
at the moment I have a project, which is of some interest for people, who are not familiar with programming, but do some electronics. T3.5 or now T4.1 is used and a SD card is used too.
Perhaps the following...
If the LEDs on the Teensy socket aren’t on then something is wrong, only one of the two LEDs are connected and it’s setup to show activity when you call Ethernet.begin().
Please use code-tags when posting code.
How do you measure this?
I had problems getting my cheap scope to trigger with your code.
I think you just did'nt see the pulses.
The code below works better:
Don't...
I noticed that the LEDs on the ethernet socket of my laptop are on/flash, but the ones on my teensy not. Is it possible, that the socket on the Teensy is defective?
