Node Spot Heating

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Node for paying for spot heating. It is a variation on the payment terminals used for coffee and beer.

See SpaceTegoed voor een overzicht/plan, Payment and Paring REST protocol for the protocol and [github for code].

What does it do

Swipe ones to get 15 minutes of heating. Swipe twice for 30 minutes; and so on. The display will show 15:00, 30:00 and so on. And then change every second to 14:59, 14:58 and so on.

Once you've swiped - the display changes from the price to a countdown.

During this time the heating is on. Once it reaches 00:00 - the heating switches off.

Trouble shooting

It is possible to 'telnet' into these units (on the normal telnet port #23) and see what normally would come out of the serial port. The units also sent their logging to syslog (to the spaceserver, 192.168.6.1).

Check the firewall, use a [MDNS] [resolver] (or simply the Arduino IDE) to discover their IP address. You can do this from the RaspPi next to the VinylCutter / Vinylsnijder.

MAC	Versie	Mac address	IP address
NodeSpotHeating	1.65	????	192.168.6.???

Version deployed as of September 2022: https://github.com/dirkx/makerspaceleiden-payment-node-7segments/releases/tag/v1.06

A typical session looks like:

$ telnet 10.13.0.241 23
4x7-F1-05-430fe4 Serial connected 3C:71:BF:43:0F:E4
Good scan
Payment completed successfully.
Wed Nov  3 19:02:11 Heap: 181 Kb

Any error message (post joining the Wifi network) will show up here. If the issue is prior to joining WiFi - you will have to connect a USB cable (Baudrate 115200, 8N1). The Raspi has the right drivers installed.

Furthermore - if you connect to space.makerspaceleiden.nl via MQTT - then you can also see the output:

TOPIC: ac/log/tft-1.04-cbb67c 
   NodeSpotHeating {
  "rfid_scans": 0,
  "rfid_misses": 0,
  "ota": true,
  "state": 3,
  "IP_address": "192.168.6.200",
  "Mac_address": "C8:C9:A3:CB:B6:7C",
  "Paid": 0,
  "Version": "1.04",
  "Firmware": "tft-1.04-cbb67c",
  "heap": 139667
}

Display messages

1. During startup
   1. F X-YY - version number firmware during booting.
   2. CONN - connecting to WiFi
   3. NTP - getting the time
   4. F CA - Fetching the Certificate Authority
   5. F PL - Fetching the price list
   6. FAIL - failed to connect to WiFi; will reboot.
   7. any error message - scrolling error message & after which either reboot or hang if it unrecoverable.
2. At the end of startup (from this point onwards OTA is possible).
   1. ---- - fully started up; but have not yet gotten the pricelist
   2. no prices - price list could not be fetched. Will retry for a few minutes every 15 seconds; then reboot.
3. In normal payment mode
   1. X.YY - price to pay when you swipe
   2. [--] - in the process of paying
   3. paid - you have paid
   4. MM:SS -- a minute and second countdown. Once at zero - the heating switches off.
   5. FAIL - payment failed
   6. any error message - scrolling error message.
      1. FAIL -1 - netwerk/wifi error. Powercyle de unit.
      2. FAIL -4 - netwerk/wifi error. Powercyle de unit.
      3. FAIL 40X Gebruik je een geldige tag ?
      4. FAIL 500 Error op de server; mail noc@.
4. During Over the Air reprogramming.
   1. PROG - start of OTA update
   2. F XX - OTA; uploading new firmware; XX is the percentage fetched
   3. DONE - successful end of OTA. Unit will reboot.
   4. any error message - scrolling error message & after which the device will switch back to the old/current firmware
5. During initial pairing / post an OTA
   1. REG Registering with the server
   2. PAIR requesting to pair; swipe an admin tag.
   3. any error message - scrolling error message.

Code is at https://github.com/MakerspaceLeiden/makerspaceleiden-payment-node-7segments.

Bill of materials

Materialen; duurste onderdelen eerst:

1. ESP32: 7 euro - https://www.amazon.nl/AZDelivery-Development-opvolger-compatibel-Inclusief/dp/B074RG86SR/ref=sr_1_9
2. PVC Doosje:
3. 7 segment display: 2.50 euro - https://www.amazon.nl/Youmile-Display-Gemeenschappelijke-Digitale-Man-vrouw/dp/B082193P1V/ref=sr_1_33
4. 1 RFID reader; ~2.50 Euro; (https://www.amazon.nl/gp/product/B074S9FZC5)
5. AC/5V transformer: 1.00 euro - https://www.aliexpress.com/item/33012749903.html
6. 1 relays - 5 Volt, voor 230 VAC / 2000 watt.
7. 3 doorvoerwartel; 12mm: 0.35 euro (voorraad space, https://www.aliexpress.com/item/32866592761.html)
8. netsnoer - weggooikast space
9. draadjes - electronica hoek
10. drie tie-wraps (voorraad space)

Totaal: < 20 euro; 4 uur printen; 30 minuten solderen/assemblage.

Compileren software

1. Installeer een recente versie van [[1]].
2. Installeer een stable versie van de SDK voor de ESP32 volgens https://docs.espressif.com/projects/arduino-esp32/en/latest/installing.html
3. Selecteer in tools het platform ESP32 en dan het board dat je gebruikt (WRover, Devkit)
4. Installeer via de 'Library' optie de bibliotheken MFRC522-spi-i2c-uart-async, TM1637TinyDisplay en Arduino_JSON
5. Haal een git/zip versie op van https://github.com/MakerSpaceLeiden/makerspaceleiden-payment-node-7segments/
6. Zet de #defines met de netwerk namen goed. Kies een unique terminal naam.
7. Overleg met noc@ voor een 'bearer token' voor toegang als je de productie versie maakt.
8. Idem voor het OTA wachtwoord.
9. Compiler & flash via serial (daarna kan het via OTA).
   1. Nota bene: with the cheaper boards; it may be needed to press 'BOOT' during the start of the programming.

Versions build

Node Spot Heating

• Wifi-Mac address ends with XXXX

Current software: https://github.com/dirkx/makerspaceleiden-payment-node-7segments/releases/tag/v1.06