JasonACT Posted January 25 Author Share Posted January 25 I've pulled that chip off the test board, and expect to get a 4/5ths refund, because my seller here advertises that I should be getting the exact chip I wanted - and I didn't. But since I've got the test board sitting around, I thought to test the ESP PSRAM16H (2MB) chip I did most of my development with (I pulled this one off an ESP32-S2 board that has bugs in the Arduino software that ESP released - so I couldn't use it reliably without it locking up - well over 2 years later they know it's an issue, but don't care to fix it)... This ESP chip works perfectly, even with my bad SD card, all the way up to 141MHz passing with no errors. 2MB is rubbish though, but this has survived being pulled from a board 2 times and soldered on 3 times. Not bad... 1 Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted January 26 Share Posted January 26 17 hours ago, JasonACT said: @RickyDean As you can see from my picture here, this chip (plus 3 others in the 5 I bought from Adafruit) has the surface sanded off. Only one of mine was a real ESP chip with the company logo still showing - and that's the one that worked. I've now tried another one and it's also failing, though it gets a little bit further, the fail point is 131MHz. Can you check what they sent you and let me know if you can see the ESP logo on any of the chips? EDIT: I've written an email to my supplier here asking what's going on in my case, we'll see what they say. Sanded chips are a bad sign 99% of the time (the other 1% of the time, the OEM sanded them when they first installed them to make it harder for outsiders to easily figure out what chips they were using on their boards--and with the proliferation of chip testers, that doesn't make sense anymore). 2 Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 26 Author Share Posted January 26 (edited) Yeah, I'm not at all happy with what I was sent, the bent pins I had mentioned previously must have been when the sanding occurred, but I've again put one of the sanded-top-surface chips back on the board and tried one last thing (and it's not been tested on a real TI, this is only "on the bench" software testing - so there's no knowing if this actually works as a proper solution)... I've cut the SD card's clock trace and used a 470 Ohm resistor to reconnect it to the clock on the PSRAM. The idea being, the PSRAM will get the full signal, since it's running at over 100MHz, but the SD card running at around 25MHz will still work with the weaker signal, but the SD card won't sink too much current to disturb the PSRAM. This passes the bench memory test at up to 135MHz for the PSRAM and the SD card does comfortably lists its full directory at 25MHz before the test starts. I don't think this PSRAM chip was the worst one I had tried though, I had cleaned them all up to send back to my seller, and I guess I'm keeping this one, but one of them was really bad from the notes I had made. Edited January 26 by JasonACT grammar 2 Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 26 Share Posted January 26 (edited) 8 hours ago, JasonACT said: Yeah, I'm not at all happy with what I was sent, the bent pins I had mentioned previously must have been when the sanding occurred, but I've again put one of the sanded-top-surface chips back on the board and tried one last thing (and it's not been tested on a real TI, this is only "on the bench" software testing - so there's no knowing if this actually works as a proper solution)... I've cut the SD card's clock trace and used a 470 Ohm resistor to reconnect it to the clock on the PSRAM. The idea being, the PSRAM will get the full signal, since it's running at over 100MHz, but the SD card running at around 25MHz will still work with the weaker signal, but the SD card won't sink too much current to disturb the PSRAM. This passes the bench memory test at up to 135MHz for the PSRAM and the SD card does comfortably lists its full directory at 25MHz before the test starts. I don't think this PSRAM chip was the worst one I had tried though, I had cleaned them all up to send back to my seller, and I guess I'm keeping this one, but one of them was really bad from the notes I had made. Well here is the first and second of the unopened ESP-PSRAM64H Adafruit 4677's. The chips obviously looks to be somewhat sanded, and virtually impossible to read the information on top on the first one, a bit better on the second. I think I got these from Mouser. Edited January 26 by RickyDean 1 Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 26 Author Share Posted January 26 15 minutes ago, RickyDean said: Well here is the first and second of the unopened ESP-PSRAM64H Adafruit 4677's. The chips obviously looks to be somewhat sanded, and virtually impossible to read the information on top on the first one, a bit better on the second. I think I got these from Mouser. They look a whole lot better than mine, that's for sure. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 26 Share Posted January 26 (edited) 9 minutes ago, JasonACT said: They look a whole lot better than mine, that's for sure. Well, I checked them all even the two I used and they all were sanded on top, most of the 10, illegible to read. I'm going to contact Mouser and see what they will do. Edited January 26 by RickyDean spelling Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 27 Author Share Posted January 27 4 hours ago, RickyDean said: Well, I checked them all even the two I used and they all were sanded on top, most of the 10, illegible to read. I'm going to contact Mouser and see what they will do. I'm still waiting for my seller to get back to me, but good news, I've built up the unit with the SPI clock resistor now and... it passes the SAMS 1MB test... I now have too many working PPPEBs... But not enough 74LVC245s or Pico-Ws with the header pins soldered the right way (that's my original test Pico, and I wanted the pins sticking up, not so much now). 5 Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 28 Author Share Posted January 28 @RickyDean I think you can remove R4 and that might give you a small performance increase with your PSRAM chips. It does for me. R4 was there in the original design for the SD card's data out pin, so if no SD card was inserted, the Pico's data in pin wasn't left floating. With the PSRAM installed though, something is always connected (even when in high impedance mode, there will be "something" there). The bench memory tester only ever shows better results for me when R4 is not installed. I've changed the circuit board design to include a new R4 (in a different location) that can be used for the 470 Ohm clock resistor, if needed for troublesome PSRAM chips (or otherwise, just a wire is needed in that location). I'm not planning to have any more boards built myself though, so I'll hold off posting any updates to the Gerber files until you finish your testing. Oh, I did build one more minimum board (risers, PSRAM and SD socket only) and I found and used the really bad PSRAM chip I had previously tested... It fails at 126MHz with an SD card inserted, 140MHz with no SD card, and 132MHz with the 470 Ohm resistor - and passes a full 8MB bench test (12 x 4 test types just like the TI does - except with more aggressive timing) at 129MHz. I think I can use even this really bad chip. 1 Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 (edited) 19 minutes ago, JasonACT said: @RickyDean I think you can remove R4 and that might give you a small performance increase with your PSRAM chips. It does for me. R4 was there in the original design for the SD card's data out pin, so if no SD card was inserted, the Pico's data in pin wasn't left floating. With the PSRAM installed though, something is always connected (even when in high impedance mode, there will be "something" there). The bench memory tester only ever shows better results for me when R4 is not installed. I've changed the circuit board design to include a new R4 (in a different location) that can be used for the 470 Ohm clock resistor, if needed for troublesome PSRAM chips (or otherwise, just a wire is needed in that location). I'm not planning to have any more boards built myself though, so I'll hold off posting any updates to the Gerber files until you finish your testing. Oh, I did build one more minimum board (risers, PSRAM and SD socket only) and I found and used the really bad PSRAM chip I had previously tested... It fails at 126MHz with an SD card inserted, 140MHz with no SD card, and 132MHz with the 470 Ohm resistor - and passes a full 8MB bench test (12 x 4 test types just like the TI does - except with more aggressive timing) at 129MHz. I think I can use even this really bad chip. Okay, I've been working with the board without a riser, replaced the ESP chip with another of the new APS6404L-3SQR chips and placed a 470 ohm resistor, as you did. Still not working right. Edited January 28 by RickyDean subtracted content 1 Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 28 Author Share Posted January 28 33 minutes ago, RickyDean said: I've been working with the board without a riser Can you post up a photo of that board, I'd like to see it, though I expect it won't help? What's the memory tester doing in regards to flashing the LED? Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 19 minutes ago, JasonACT said: Can you post up a photo of that board, I'd like to see it, though I expect it won't help? What's the memory tester doing in regards to flashing the LED? With SD card 1 blink every 5 seconds, w/o SD card 0 blinks after initial flashing. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 36 minutes ago, JasonACT said: Can you post up a photo of that board, I'd like to see it, though I expect it won't help? What's the memory tester doing in regards to flashing the LED? Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 28 Author Share Posted January 28 @RickyDean I can't see where you have cut the trace, like I did here: Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 The one with the risers, with SD card 1 blink every 5 seconds. 14 w/o card Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 1 minute ago, JasonACT said: @RickyDean I can't see where you have cut the trace, like I did here: Okay, didn't see that, so I do that. Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 28 Author Share Posted January 28 @RickyDean Is there some steel wool contaminate left on your Pico? Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 Okay first one with SD card 8 blinks, w/o SD card 0 blinks. Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 28 Author Share Posted January 28 5 minutes ago, RickyDean said: Okay first one with SD card 8 blinks, w/o SD card 0 blinks. That's also what I get with my really bad PSRAM - but that should work with the 12mA .uf2 software. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 7 minutes ago, JasonACT said: @RickyDean Is there some steel wool contaminate left on your Pico? No not steel wool, some fuzz. I took it outside after soldering the new memory chip on, to spray the flux off with cleaner and dropped it on the ground. Apparently didn't clean it as well as I should have.. 1 Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 2 minutes ago, JasonACT said: That's also what I get with my really bad PSRAM - but that should work with the 12mA .uf2 software. Which was the post with the 12ma software. Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 28 Author Share Posted January 28 On 1/18/2024 at 5:57 PM, JasonACT said: Something for tomorrow then before pulling the chip... One last version to test, slightly slower (the minimum working speed to pass my tests) 256MHz/128MHz and 12mA (the maximum digital I/O setting) - 12mA allowed me to overclock the ESP chip to 134MHz and pass the test successfully. PPEB2.ino.uf2.zip 379.09 kB · 4 downloads This one But I'm now using 258MHz & 12mA because I don't like it being "on the edge" of working... 256 was the minimum - and 8 blinks should work with 258. I'll upload a new version if this one works for you. Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 With Riser 6 blinks with SD, 14 w/o Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 28 Author Share Posted January 28 4 minutes ago, RickyDean said: With Riser 6 blinks with SD, 14 w/o That's on the edge, for sure. Failing at 260/130MHz, maybe the 256/12mA software will work though, using the 258/12mA might show random issues - especially if it's bumped on the desk... The risers are probably introducing a small amount of resistance. I wiggled my Pico in them to make it better, that might work for you? Quote Link to comment Share on other sites More sharing options...
RickyDean Posted January 28 Share Posted January 28 5 minutes ago, JasonACT said: That's on the edge, for sure. Failing at 260/130MHz, maybe the 256/12mA software will work though, using the 258/12mA might show random issues - especially if it's bumped on the desk... The risers are probably introducing a small amount of resistance. I wiggled my Pico in them to make it better, that might work for you? The one without risers, failed both with and without SD card. The riser one is still testing with SD, hasn't finished yet Quote Link to comment Share on other sites More sharing options...
JasonACT Posted January 28 Author Share Posted January 28 (edited) 11 minutes ago, RickyDean said: The one without risers, failed both with and without SD card. Wow, when it failed, did the 2nd read show the correct value? That was my test for an actual bad memory chip. Edit: Have you removed R4 on both boards too? Edited January 28 by JasonACT Query about R4 Quote Link to comment Share on other sites More sharing options...
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