Heltec Dev Boards

In my opinion, your parts are fine as is at the moment. We are still working on figuring out what the current standards should be. The ones we have are old, and sometimes wrong, and there is no one left who knows what the original intent of some of the stuff was. We need to read the source code and try and figure out what some of this stuff does (or in some cases is supposed to do, because it may not be implemented yet.) In any case here is a part for the Kit 32 part @EmitWheasel asked for, I’d advise waiting til someone at Heltec has looked the part over because some of the descriptions may be wrong (I think the part should be correct though if you need it in a hurry!)

Heltec WIFI Kit 32.fzpz (48.7 KB)

Now on to what I did to the Heltec WiFi LoRa 32 V2.fzpz part I cloned this from and why I did them.

I first ran the Heltec WiFi LoRa 32 V2.fzpz through FritzingCheckPart.py, its only complaint is that there are missing layerIds for breadboard and schematic (which is correct due to a case issue) which will mean the part won’t export as a svg or pdf, and that the scale on the svgs is wrong (which doesn’t affect function in any way.)

breadboard:

ungroup the svg (needed to rescale it) which had the side effect of deleting most of the pins as they were defined as groups rather than as the id of a circle drawing element. The purpose of rescaling is to make the viewbox conform to the recommendation that one drawing unit be 1/1000 of an inch in the part file format document. Instructions for doing it in Inkscape are available here:

Then I set the text font-size a uniform 25px for all the pin labels and added a text-anchor:middle to the style commands. That way when you change a label you don’t have to re adjust the x position to keep it in the center of the pin. I then recreated the connector definitions that had been groups as the id of the circle for the pin and moved them all to the bottom of the xml editor window. The reason for this is that I have a python script that will allow me to set, add, or modify connectors in an svg as long as they are the last elements in the svg (it also makes finding the pins in Inkscape easier as they are sequence at the bottom of the xml editor window.) Changed the text on the pin labels to match the pin out for the Wife Kit 32 documentation. Resized the svg, edit->select all, then regrouped and named the group “breadboard” (case needs to match the layerId label in the fzp file, in the original part the group label is “Breadboard” which doesn’t match the fzp file.) I also deleted the LoRa connectors and adjusted the components to match the pictures of the Kit 32 on the web site (although the components probably aren’t in the exact right place.)

PCB

Again ungroup and rescale the svg to standard scale. Then using a text editor, modified the pad radius to be 29 (0.078in diameter) and stroke-width:20 to cause a 0.038 hole in the pads. This is the standard hole size for .1in headers, and I assume that is usually what will be connecting to the board. In Inkscape the PCB hole diameter is:

Hole diameter = pad diameter - (2 * stroke-width)

At present I have left the pin labels in silkscreen, but added a text-anchor:middle to each, and reduced the font size to 20px to provide more space between the pad and the silkscreen border. The recommendation is to not put text on the silkscreen, because to remove it the user has to modify the part. If the text is not in the part and the user wants it, they can add it in the sketch without modifying the part. It won’t hurt anything to have the text there except if someone doesn’t want it on the silkscreen for some reason, so I left it there to match the rest of your parts.

schematic

ungrouped and rescaled the svg. In a text editor changed all the stroke-widths to be 10, the terminalId height and width to be 10 (making the terminalId a 10thou by 10thou rectangle) and checked the alignment (which was out slightly because the original values were smaller.) Then changed the text to match breadboard (and the Kit 32 pinout pdf.) Added text-anchor:start (right side pins) text-anchor:middle (center labels and the pin numbers on left and right) and text-anchor:end for the right side pins so changes in text length don’t change text alignment. Resize regroup (and name the group “schematic” to match the svg) and save as plain svg.

fzp file

The part number property is likely wrong, I couldn’t find a part number for the Kit 32 on your web site so left it as the one for the WiFi LoRa 32 V2 which is likely incorrect. The description probably needs some changes too, I changed the LoRa 32s to Kit 32 but I expect the rest of the desciption needs a proper update too (and I don’t know how to make it.) As well when adjusting the pin descriptions I came across this on pins 29 or 30 and don’t know if this is correct or not (it seems likely to me that the two touch numbers should be the same across the different boards, but that may not be correct.):

 <connector name="pin 29" id="connector28" type="male">
   <description>Pin 33, XTAL32, GPIO33, ADC1_5, Touch8</description>

is “Pin 33, XTAL32, GPIO33, ADC1_5, Touch9” in the LoRa 32 part and as noted I would expect them to be the same (Pin30 has Touch9 and Touch8 in the LoRa 32 part.) I assumed the Kit 32 pinout pdf was correct and used that in the part, but it is worth checking if that is correct. Finally I adjusted the pin numbers for the bus definitions and added a 5V bus to make the buses for this part correct and it is done.

Peter

1 Like