====== NTP Server TS01 ======

https://www.ebay.com/itm/404204890868

===== Software =====
No clue.


===== Hardware =====

==== External Interfaces ====
=== Front ===
  * SMA female for GNSS Ant
  * 10/100 RJ45
  * DC 5V input (5.5mm/2.1mm) - Marked 1A, but I haven't measured the device pulling more than 200mA
  * OLED screen - blue - 128x64 pixels. Standard i2c module.

=== Back ====
Two 10 pin phoenix-style terminal blocks, marked COM A (left) and COM B (right). The pinouts are very strange. The first 8 pins of COMA all run to the pad marked A+ on the RS485 module. The first 8 pins of the COMB block all short to the pad marked B- on the RS485 module. The last two pins on each module are also the same - pin 9 goes to the GNSS PPS pin, and pin 10 goes to the ground pin on the output side of the RS485 module (NOT the board ground!).

I think the idea is that you could run this thing to eight different systems over RS485?

Serial data is sent over this interface at 19200 baud every ten seconds. The data looks like this:

<code>
:\xB6\x16\x01\0\x17\x17\x03\x1E\x0B\x07&\x17\0\x11]\x01j\xD7N\0\x1A\xC0\0\x9B\xC5W\x94_
:\xB6\x16\x01\0\x17\x17\x03\x1E\x0B\x071\x17\0\x11]\x01j\xD5N\0\x1A\xC0\0\x9B\xC4W\x9A\x08
:\xB6\x16\x01\0\x17\x17\x03\x1E\x0B\x07;\x17\0\x11]\x01j\xD7N\0\x1A\xC0\0\x9B\xBFW\xAD\xB5
:\xB6\x16\x01\0\x17\x17\x03\x1E\x0B\x08 \x17\0\x11]\x01j\xD4N\0\x1A\xC0\0\x9B\xBDW\xBB\0
:\xB6\x16\x01\0\x17\x17\x03\x1E\x0B\x08\x13\x18\0\x11]\x01j\xD3N\0\x1A\xC0\0\x9B\xC1W$\xC2
:\xB6\x16\x01\0\x17\x17\x03\x1E\x0B\x08\x1D\x17\0\x11]\x01j\xD2N\0\x1A\xC0\0\x9B\xC2W$\x04
</code>

COMA
  - A+ on RS485 module
  - A+
  - A+
  - A+
  - A+
  - A+
  - A+
  - A+
  - PPS
  - RS485 GND

COMB
  - B- on RS485 module
  - B-
  - B-
  - B-
  - B-
  - B-
  - B-
  - B-
  - PPS
  - RS485 GND
==== Internal Interfaces ====
  * One button: Marked SW-PB, pulls the 3v3 rail of the LDO to ground through a 10k resistor
  * One LED: red power LED hanging off 3v3 thru 1k resistor
  * Red TX/RX LEDs on the UART-RS485 board

=== Headers ===

  * JP10 - 1x3 - GND | Pin 18 of GNSS (reserved???) | Pin ## on MCU - unpopulated
  * JP1 - 1x4 - R/T | R/T | GND | 3v3 - populated - suspected MCU UART
  * JPB - 2x3. First row is marked 5 on the left side, second row is marked 6. Right pins are marked 1 and 2, top and bottom, respectively. Middle pins are presumably 3 and 4, top and bottom. Pins 1 & 2 are 3v3. Pins 5 & 6 are GND. One jumper is present bridging "3" and 5. Unknown what "3" and "4" connect to. 
==== Chips ====
  * GNSS - AT6558 R-5N-32-E2 based, likely ATGM336H5N-31? - No silkscreen mark - maybe underneath?
  * MCU - CH32F103 - STM32 "bluepill" clone - Marked T32
  * NUC - WIZNet W5500 10/100 SPI - Marked U5
  * EEPROM - FT24C16A 16Kbit i2c - Marked IC15
  * ?????? - R8025 E R41 72 - Marked RX1
  * 3v3 LDO - AMS1117 3.3 - Marked U1
  * UART to RS485 module mounted on board - Marked T4

==== Curiosities ====
  * Entirely hand-assembled 
  * Small heatsinks mounted to the GNSS, MCU, and NIC - absolutely not needed
  * PPS from the GNSS is not connected to the MCU anywhere as far as I can tell. NTP server performance will suffer accordingly.
  * OLED screen mounted perpendicular to the board via a female header sitting flat is very clever!