The intention is to provide support for s14clock users. Initially it will be Q&A captured via interaction w/ s14clock users. Releases will be made periodically with feature enhancement and bug fixes, "watch" this repository for "releases" and you will be notified when new binaries become available.

• Erase and Flash All
• Flash New Firmware
• Soldering Tips

2023-06-07 V3 hardware (24 characters) released, 74HC154 eliminated. New circuit design adds charliplexing to led multiplexing to simplify design. No more SMD to solder makes a more robust kit.

2023-04-06 S14Clock build, instructional video, click to watch

2023-04-01 Word of caution for developers, the S14Clock hardware uses direct multiplexing to drive the LED segments, there are no current limiting resistors, be very carefully working on the multiplexing code blocks. If the multiplexing become interrupted, prolong current stays can damage the LED segments and / or the S2 Mini IO ports.

2023-03-26 The most common problem with soldering is cold solder joints. To avoid this you can heat the component with your iron first, then apply solder, and wait for one or two seconds before lifting your iron. See soldering tips.

2023-03-22 with 6 units of S14-24 shipped out, it is discovered that the ESP32 AP (initial setup mode) may not accept password or connection. This could happen after the unit have been "disconnect" (i.e. forget WIFI credentials) one or several times. I had discovered this while preparing assembled units to be shipped out. In this case, one need to erase the S2 mini, and flash everything (including bootloader) to correct this issue.

Post July 2023 units are of HW version 3.0, there are no more SMD components to solder.

You may discover some digits or segments does not light up, and this is caused by cold solder joints. The following map (for S14-24) allow you to trace which connections need to be reflowed to fix these joints. If you have a flew of these, reflow all joints (add flux, allow solder on joint for an extra second, etc) can help.

The following applies to HW 2.1 (pre July 2023 units)

S14-24 HW2.1 (24 character unit)

S14-12 (12 character unit)

• SEG ?? refers to segments of LED modules, you can locate them from pin labels on back of PCB
• IO ?? refers to IO port of S2 mini unit, they are labeled on the PCB footprint
• 2/4 LED modules are used for 24 characters, digit numbers are extended from left to right, i.e. DIG 24 is D6 of the 4th module.
• P?? refers to the 74HC154D chip, they are pin numbers, you have to count from pin 1 to locate joint (S14-24)
• 74HC154D is a 4 to 16 line decoder, 4 IOs from the S2 mini are expanded to 16 LED module digits (S14-24)

    ___ A
  F|\|/|B (HJK)
 G1 - - G2
  E|/|\|C (NML)
    ___ D

When you have ghosting or multiple digits or segments light up when they shouldn't, you may have solder bridges or excessive solder on certain joints (which is adjacent to very thin traces nearby). Try to reflow 74HC154D and remove excessive solder (by wick or other means) if it appears that there are too much.

• Erase unit and flash everything (including bootloader) again
• Use Chrome or Edge browser on your PC / notebook, navigate to Adafruit ESPTool.
• Plug in your unit and click "Connect" (upper right corner) on the ESPTool page. Look for the ESP32-S2 entry. If you do not find it, put the unit to programming mode by holding down the '0' button and press 'Reset'. Try click "Connect" again on the ESPTool page.
• Select the ESP32-S2 entry and hit "Connect".
• Click the Erase button to erase unit's flash space. This will take a few seconds.
• Enter offsets and bin files accordingly;

Bin files can be download from the s14clock source repository, bin directory, select the proper version and variant. Ex. firmware24_v202.bin, firmware24_201.bin for 24 character unit V2.1 firmware. Version 2.0.2 and above has common firmware binaries supporting all hardware variants (both 12 and 24 character) via HW detection. You have to select and click on the file of choice, then locate and click on a download (download raw file) icon to initiate the download.

Procedure is similar to Erase and Flash All Skip "Erase" and flashing only firmware????.bin at 0x10000 if you only want to upgrade firmware. Bin files can be download from the s14clock source repository, bin directory, Ex. firmware24_201.bin for 24 character unit V2.1 firmware.