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So are you using 18650 cells? I'm using single cells in parallel (2.8v to 4.2v) using a battery management chip (an easier circuit option is the bq25892) which includes charging as well automatic power path charging and switching from usb and solar. I also use a max17201 fuel guage The output...

If your looking for power savings I got rid of the 3.3v linear regualtor and power mine off a 3.3v buck booster TPS63020 (which is supplied by a BQ25798 power management chip) ive had no troubles with power quality You need too use a couple mosfets to help delay the power on stage. But if you...

Paul has shown a lot of restraint, I expected this thread to be locked now. But it is an interesting point. If one was to make a diy teensy (with Paul's bootloader of course), expose more pins, add an imu or whatever and call it something completely different. (Eg "The Mega" Could then this...

So someone could buy 1000 bootloaders, design a 'toonsy', make 1000 of them and sell them?

There's definitely a bit of misinformation in that thread. You can most definitely sell your commercial product with a teensy embedded inside The only thing not open source is the bootloader IC. And that's purely to stop the Chinese copies. The core is all accessible, editable etc...

And here I was hoping you were going to drop on us a 4.1 wifi accessory board with all the software ready 😉

Not sure why your trying to advertise a competing product on the pjrc forum. If you honestly wanted a competing product to teensy. go the imxrt1170. Dual core. 1ghz. Everything teensy 4 has but more. But be prepared to to realise how much work Paul has put into making Teensy 4 software (and...

So has anyone managed to make something useful from this yet? I'm curious, is this meant to be purely a hobbyist thing, or is it meant to be a 'design your own board' for a product thing.

There is way too many layers of abstraction going on here, and that's just the pc software side.

That's a long time. Waiting 25 seconds for a boot up I don't get the hype in the microcontroller world for this. It's not a microcontroller, but a microcomputer. More so to compete with the Pi. Add to that everything seems so undeterministic.

That's a long boot time. Is that just first boot or every boot?

So i have had a play with the SDRAM Pad Settings. I have managed to get SDRAM running stable at 240mhz My original problem from going 198 to 221 was pad EMC_08. Just adjusting the rate on that made it stable to 227mhz. Doing some tests clearing an 800 x 480 x 16bit back buffer while the...

Day 18. A truck drove by, emblazoned on the side with a big Q. I refuse to go to the dark side, even if it means rescue....

As per the post above, that was fixing the SDRAM to not fail on reads when running at 221mhz So the problem i had was a bunch of extra pins not accessible through the standard digital write, as they where not defined. Also trying to map existing pins was a bit tricky and i didnt want to edit...

I wonder what the boot up time will be for the Linux soc. Milliseconds? Seconds? Tens of seconds?

Massive corporation buying up small company never ends well. Large companies are always profit driven. Theyre already releasing a completely new different ide. Soon you will be having to create a qualcom account. Any new boards will have to go through the new ide. 'Qualcominos' will...

I'm not a fan and I think the buyout of arduino is not good news. To me a micrcontroller should be predictable and barebones. Not running an RTOS or Linux etc.

So anything lower than 30mhz is giving you artifacts? A lot of artifacts? I think the data sheet recommends a 25 mhz clock. This gives about a 60hz refresh rate. I've got mine set to 20mhz for a 50hz refresh rate.

I'm using the same display haha. Am using just the PT4110 recommended from buy display.

Hey, has there been any more progress on this?

Great! Post if it works If you get it running!

What about a power latching circuit with push button reading With power button held down, circuit will always turn on. As Microcontroller boots up, first thing you do is MC_Latch_On pin to high When everythings on If you press the button , MC_Button_Sense will go low. record if it goes low...

So I finally got around to doing some more on this. After a bit of testing I've realised the sdram test was failing only on 32 bit reads. Setting the test buffer to 16 bit there would be no failures. So on the second burst of the read it must have been failing? (16 bit data bus to read 32...

If you like I can upload the symbol and schematic I used for my DIY board with sdram. I outputted pretty much every pin that could be used. I used the larger 12x12 version of the chip with a 4 layer pcb, and hand solderable (smallest components is 0603) with only 2 capacitors on the back The...

Double check your schematic carefully against the official one and make sure your not missing any connections. I head scratched 2 revisions with a 9 blinking error. Then I realised I hadn't connected 2 DCDC ground pins (n1 and n2) The power up sequence worked. The bootloader chip would get...

Those times look good. Thanks. If you can start the PXP as early as possible you can do some of it in the vertical blanking period. I haven't had any time recently to look at all this. I hate to say it, but after stumbling around trying to roll something at the time I threw it at chatgtp...

Sorry I didn't realise that. Will need someone more knowledgeable to answer that then.

So im guessing you would need to set the MUX on the pin back to standard io. You will need to know what bank you are using and the pin. IOMUXC_SW_MUX_CTL_PAD_GPIO_B0_00 = The different configurations for the pins are in the datasheet

I've never used LVGL but it always seems to pop up with microcontrollers etc. Do you design your ui on a pc or something rather than hard coding things? Sorry I wasn't very clear. I'm not using the PXP for scaling or rotation. This is done in software on the cpu. It's reading a stored image...

So will this fall within your use case of copying buffers from lvgl? Doing some test image Scaling, Rotation and transparent pixels. All running at 50hz done in software Source image is 128 x 128.

Very nice!!! The 800 x 480 x 2 seems pretty quick. As an aside. You could try and allocate the buffers into different banks of memory (think it's 4 x 4mb each spaced sequentialy) im curious if that makes a difference. I believe there's a little less switching required on the sdram.

How are you doing the copy sdram to sdram? Just a memcopy? I found it faster to burst read an image row (800 x uint16_t) into a local buffer on the stack, then output that in a burst back to sdram.

Yes its a pretty good panel. I had the non IPS version from them before which was not as good (When viewing from the side the colours seemed to change) The only downside is the 2 Ziff cables are far away from each other. I had gone away fromm the pixel pipeline but found an old build with it...

Interesting!!

Whats interesting. Zooming in is actually a lot faster too. As when we are zoomed in there is a lot less of the source image to read from sd ram (We only read the rows required to go to the destination image) So zoomed in at its peak in the video is only 5 milliseconds to read SDRam, scale...

Did some nearest neighbour image scaling using software. (I'm pretty sure the PXP uses nearest neighbour too) I couldnt get Bilinear filtering work, however i think that would be way to slow in software Nearest neighbour is quite quick. Reading and writing non scaled 800 x 480 image from...

I tried some full sized images, 800 x 480 in 24 bit packed format. Not using the pixel pipeline. The fastest i could get was: Image in SDRam, reading from SDram then copying into the Backbuffer on SDRam. 13.9 milliseconds Image saved to onboard Flashmem. Then read to back buffer. 16.2...

I did some tests running the backbuffers and display in rgb565 mode (Sdram clocked at 198mhz again) Backbuffer size is 384000 * uint16_t. All this is done while the LCDIF is outputting to the display at 50hz Pixel Pipeline time clearing the backbuffer with no CPU access. 8.66 milliseconds No...

Sure. Give me a bit though to tidy it up. At the moment im running 3 seperate projects for simplicities sake. 32 bit, 24 bit and 16 bit, as all the primitive drawing routines take in different colour values. Exactly! It took me the third itteration to get this board right. The first 2...

Thats interesting to know. Thanks Yes. Unfortunately at least the LCDIF will be reading the Sdram while anything else is going on with it. I don't remember how much exactly, but setting the backbuffers in different banks (The SDram is divided into 4 even banks) did make a difference on...

I ordered one of dogbones boards and got it stable at 221mhz with a 10pf capacitor. However I think the routing for the sdram for that board was a replica of the imxrt1060 dev board. There routing pattern would be professional. I can get my board running at 198mhz with or without the...

I've tried many different capacitor values, and i cannot get it to run stable at 221mhz. The best i got using a 20pf capacitor, was using Dogbones Sdram test slightly modified was an average failure rate of 3500 words every 478 million word reads So now ive been doing some testing on an 800...

For what its worth. When sending gps locations I like to use int32_t and multiply the double location by 10 million Using 4 bytes this gives 1.1cm precision Storing gps locations in a float gives best case 1.1 meter precision.

It makes me wonder how well an SRAM chip would compare performance wise. Something like 4 Megabyte IS61WV204816BLL-10TLI. The imxrt1060 datasheet does say the memory controller supports external Sram...

Good idea. I'll give that a go!

Thanks. I'll try a bunch of different values and see if I can get an improvement. It's always bits 8 to 15 that error out (when reading the 32 bit words)

Yes I tried a 10pf and a 6pf. But ive put it down to my lack of professional routing skills. And also in trying to keep power filtering capacitors all to one side of the board they would not be optimally placed.

Thanks! Definitely wouldn't have been able to do it without you and rezo

No you would have to route one yourself. I didn't have any use for one and initially was just going to be 3.3v only. I added 3.3v regulator to be able to power of 5v usb.

I've designed a DIY Teensy 4.1 based board with Sdram with the idea of being able to solder it yourself. (It requires a stencil and solder paste as well). I don't have a hot plate, so i have been heating them with hot air from underneath. It uses the BGA 12x12 chip. Like dog bones board it...