Does this Think Plus board support either JTAG or SWD In-Line Debugging? Essentially, are the ESP32 chip pins supporting this feature of the chip brought out to the header pins?
It doesn’t look like it to me https://cdn.sparkfun.com/assets/3/9/5/f … sheet2.pdf
This board https://www.sparkfun.com/products/19177 schematic https://cdn.sparkfun.com/assets/4/5/f/c … ic_v10.pdf with an already broken-out JTAG might be a better bet; you may be able to map the same pins used on that board and backdoor the ThingPlus version? I’m not sure, but that might be possible too
TS: First issue, I am logged into the forum but found NO way to get to this post and your reply without starting from the topic ESPSystem on a chip. I only found about this reply of yours because Molly replied to my submitted question to sales hoping to get a direct answer. Why am I not given a notification or email that the forum posted question has received a reply?
I read your reply showing the graphical datasheet and noting that the Red Board 19177 may be a better board compared with the Thing Plus 20168 because sit has a JTAG connector on the board. I agree with your new board suggestion. But first to more info from Molly Sales Suport.
Molly said that tech support members sent to her several comments which she provided as a screen shot (attached). I have read the suggested PDF from Espressive and on page 24, I see that JTAG uses MTMS = GPIO14, MTDO = GPIO15, MTDI = GPIO12 and MTCK = GPIO12 for this ESP-WROOM chip. In the graphical datasheet of the 20168 Thing Plus, these signals/gpio pins are shown - see the upper left corner. Does this not imply that JTAG chip pins are available as board pins? Your reply: “It doesn’t look like it to me”. Can you review what I have just offered w/r to your point? Of course, this implies that the chip pdf and the Thing Plus 20168 are the same chip.
This attached screen capture refers to some document of unknown name/origin states that “JTAG pins are broken out on the board/ However, the debugging feature is only available through the ESP-IDF”. It continues: “Note: Users should be aware that GPIO 13 is connected to STAT LED with a pull down resistor.” This last part is curious because the Espressif PDF states on Page 24 that : ?O12 should be kept low when the module is powered on." SO which is it GPIO 12 or GPIO13 that is held low? Can you check the schematics of the Thing Plus 20168; I will also do that.
I will investigate ESP-IDF because I was hoping to use the VSC/PlatformIO debugging feature. But first can I use the 20168 or is your suggestion 19177 a better choice. I need to investigate more about that Red Board 19177.
I will keep logged into the forum and at this topic for replies.
TS: Just reviewed the Circuit Diagram for the 20168 which shows WROOM-32E and as you suggested the JTAG pins are NOT brought out, well two (TDI & TDO) are but two (TMS & TCK) are not. Thus, irrespective what info from Molly’s Contacts, I think I will use the RedBoard 19177 you suggest as the JTAG connects are on the board - although not with header pins - little matter. I also checked the 19177 circuit and didn’t find any pulldown resistors associated with that RedBoard. Thank you for this help; I only wish SparkFun forum had some notification system - OR if it does, now do I enable it?
Now I need to know how many Serial UARTs, e.g. Arduino Serial exist other than the USB-Serial version. I will check the examples and librarys associated with the 19177. Perhaps, this likely belongs as a new topic, agree?