Curiosity
LilyGO T-SIM7070G ($29.01, variante T-SIM7070G CH9102 [Q323]): all-in-one battery-tracker dev board SIM7070G NB-IoT + Cat-M + 2G fallback (GPRS/EDGE) + ESP32-WROVER-E (8MB PSRAM, 4MB Flash) + CH9102 USB-UART bridge + 18650 holder + Solar input. Stesso form factor “stick” della famiglia T-SIM.
Differenza vs T-SIM7080G S3: ESP32 classico (vs ESP32-S3 moderno), CH9102 (vs USB nativo S3), chip SIM7070G ha 2G fallback (vs SIM7080G solo NB-IoT+Cat-M), MA noto bug GPS+TCP simultaneo (reference_simcom_lpwa_chips.md).
🗺️ Pinout completo
Modem SIM7070G ↔ ESP32
| Funzione | ESP32 GPIO |
|---|
| PWR | GPIO 4 (PWR_KEY del modem) |
| TX (ESP32 → Modem RX) | GPIO 27 |
| RX (ESP32 ← Modem TX) | GPIO 26 |
| DTR | GPIO 25 |
| LED status | GPIO 12 |
I2C bus
| Funzione | ESP32 GPIO |
|---|
| Wire_SDA | 21 |
| Wire_SCL | 22 |
SPI (TF Card)
| Funzione | ESP32 GPIO |
|---|
| VSPI_MOSI | 23 |
| VSPI_MISO | 19 |
| VSPI_SCK | 18 |
| VSPI_CS | 05 |
Serial debug
| Funzione | ESP32 GPIO |
|---|
| Serial TX | GPIO 1 (UART0) |
| Serial RX | GPIO 3 (UART0) |
ADC / Touch breakout
GPIO 32-35 (ADC04-07), GPIO 25/26 (DAC1/DAC2 = ADC18/19), GPIO 27 (TOUCH7=ADC17), GPIO 4 (TOUCH0=ADC10), GPIO 2/15 (TOUCH2-3), GPIO 14/13/12 (TOUCH6-4-5), GPIO 39/36 (S_VN/S_VP=ADC03/02), GPIO 0 (TOUCH1=ADC11).
Power
- 3V3 out
- VBAT input (LiPo)
- VIN input
- GND
Specs tecniche
| Parametro | Valore |
|---|
| Modem | SIM7070G NB-IoT + Cat-M + GPRS/EDGE (2G fallback) |
| MCU host | ESP32-WROVER-E (Xtensa dual-core 240 MHz) |
| Flash | 4 MB |
| PSRAM | 8 MB |
| WiFi | 802.11 b/g/n |
| Bluetooth | v4.2 BR/EDR + BLE |
| USB-to-UART | CH9102 |
| Charging | onboard via USB-C |
| Slot SIM | Nano-SIM only |
| TF Card slot | SPI |
| LiPo holder | 18650 onboard + Solar input ⭐ |
| Antenne | LTE main + GNSS (entrambe IPEX) |
| Protocolli embedded | TCP/UDP/HTTP/HTTPS/FTP/TLS/DTLS/PING/LWM2M/CoAP/MQTT |
| GNSS | GPS + GLONASS + BeiDou (no Galileo) |
| Peripherals | I2C, SPI, UART, SDIO, I2S, CAN |
| Prezzo | $29.01 |
🧪 Use case Visla
| Scenario | T-SIM7070G ok? |
|---|
| Visla Tag NB-IoT puro | ⚠️ T-SIM7080G S3 meglio (no bug GPS+TCP) |
| Visla v2 con 2G fallback | ✅ unico LilyGO con GPRS/EDGE in rete |
| Visla v2 zone rurali no NB-IoT | ✅ 2G backup salva la giornata |
| Tracker veicolare GPS+upload contemporaneo | ❌ bug noto SIM7070G — usare SIM7000G/A7670 |
| Solar-powered remote sensor | ✅ Solar input + 18650 + low-power NB-IoT |
⚠️ Caveat noti (dal customer feedback)
- ❌ Bug SIMCom SIM7070G: GPS attivo + TCP insieme non funziona (a differenza del SIM7000G che lo supporta). Per tracker con upload+GPS contemporaneo, sceglire SIM7000G o A7670E. Memo
reference_simcom_lpwa_chips.md
- ⚠️ TCP/MQTT challenging: review utenti riportano connessioni inaffidabili — meglio AT commands raw che TinyGSM
- ⚠️ ESP32 non rileva fully charged: PMIC mancante (vs T-SIM7080G S3 che ha AXP2101) — software charge complete via voltage threshold
- ⚠️ CH9102 driver Windows/Mac: meno comune di CP2102/CH340 — su macOS Sonoma+ funziona nativo, su Mac vecchi serve driver WCH
- ✅ 18650 + Solar Input = ottimo per outdoor remote tracker
🆚 Confronto vs T-SIM7080G S3
| Aspetto | T-SIM7070G | T-SIM7080G S3 |
|---|
| Modem | SIM7070G | SIM7080G (più nuovo) |
| 2G fallback | ✅ GPRS/EDGE | ❌ no 2G |
| GPS+TCP simultaneo | ❌ bug | ✅ |
| MCU | ESP32-WROVER-E | ESP32-S3 (moderno) |
| USB | CH9102 bridge | USB-OTG nativo S3 |
| PMIC | manuale | AXP2101 dedicato |
| Solar input | ✅ | ✅ (via AXP2101) |
| 18650 holder | ✅ onboard | ❌ MX1.25 LiPo esterno |
| TF Card | ✅ | ✅ |
| Prezzo | $29.01 | $36.02 |
| Visla Tag use | con bug → no | ⭐ vincitore |
| Rural 2G fallback | ⭐ vincitore | ❌ no fallback |
🔗 Risorse