SIM7000

Connects over

UART (serial)

Made by

SIMCom

Datasheet

simcom.com

Use it

hardware {
    device sim7000: SIM7000
}

every 1s {
    let value: bool = sim7000.ready()
    log("sim7000", "ready={value}")
}

The SIM7000 talks over a UART. On its own the declaration gets a free serial port; to choose the pins, declare uart modem(tx: 17, rx: 16, baud: 9600) and write device sim7000: SIM7000 on modem.

Methods

• sim7000.ready() -> bool

  true if the modem answers AT

• sim7000.registered() -> bool

  true when registered (home or roaming)

• sim7000.signal() -> int

  Signal quality 0-31 (99 = unknown)

• sim7000.send_sms(number: string, text: string) -> bool

  Send an SMS with a delivery receipt requested; retries (2 s, 5 s) only if refused before sending, never when it may have gone out

• sim7000.check_receipt() -> int

  Delivery receipt for the last SMS: 1 delivered, 0 not yet, -1 failed

• sim7000.http_post(url: string, form: string) -> int

  HTTP POST a form body over GPRS with up to 3 attempts on failure or 5xx; returns the HTTP status or -1

• sim7000.set_pwrkey(pin: int, active_high: bool)

  Tell the driver which GPIO drives PWRKEY (K) and its polarity; enables power_cycle() and full recovery

• sim7000.reset() -> bool

  Soft restart (AT+CFUN=1,1), wait for it and re-apply settings

• sim7000.power_cycle() -> bool

  Hard restart via PWRKEY: switch off (if on), then on, then re-apply settings

• sim7000.recover() -> bool

  Soft reset if the modem answers, otherwise power-cycle

• sim7000.maintain() -> int

  Call periodically: returns network status and recovers the modem if it is silent or off-network for 3 minutes

• sim7000.network_status() -> int

  0 not searching, 1 home, 2 searching, 3 denied, 4 unknown, 5 roaming, -1 no answer

• sim7000.signal_dbm() -> int

  Signal strength in dBm (-113..-51), 0 if unknown

• sim7000.operator_name() -> string

  Network operator name (empty if unknown)

• sim7000.voltage() -> int

  Supply voltage at the modem in mV

• sim7000.network_time() -> int

  Network time as Unix seconds (UTC), 0 until the network sends it

• sim7000.ussd(code: string) -> string

  Send a USSD code (e.g. a balance check) and return the network's reply text; closes any menu it opens

• sim7000.allow_number(number: string)

  Whitelist a number in code (fixed: can't be removed by SMS); up to 6 numbers in total, matched on the last 9 digits

• sim7000.next_sms() -> bool

  Read the oldest stored SMS (then deleted from the SIM); false if none

• sim7000.sms_from() -> string

  Sender of the last SMS read by next_sms()

• sim7000.sms_text() -> string

  Text of the last SMS read by next_sms()

• sim7000.sms_allowed() -> bool

  true if the last SMS came from a whitelisted number

• sim7000.sms_command() -> string

  First word of the last SMS in upper case, only for whitelisted senders (else empty)

• sim7000.sms_command_is(cmd: string) -> bool

  true if the last SMS is a whitelisted command equal to cmd (case-insensitive)

• sim7000.sms_arg_int() -> int

  First number after the command word of the last SMS (e.g. SETID 7 → 7); -1 if none or sender not whitelisted

• sim7000.sms_arg() -> string

  Second word of the last whitelisted SMS (e.g. the number in SETNUM 0771234567)

• sim7000.sms_arg_is(word: string) -> bool

  true if the second word of the last whitelisted SMS equals word (case-insensitive), e.g. DOOR OFF

• sim7000.load_alert_number(fallback: string)

  Load the alert recipient saved in flash (or use fallback) and allow it to send commands

• sim7000.alert_number() -> string

  Current alert recipient

• sim7000.set_alert_number_from_sms() -> bool

  Save the number given in the last whitelisted SMS (SETNUM <number>) as the alert recipient

• sim7000.load_whitelist()

  Load numbers added by SMS (ALLOW) from flash; call once in setup

• sim7000.whitelist_add_from_sms() -> int

  ALLOW <number> from a whitelisted SMS: 1 added, 0 already allowed, -1 bad number, -2 list full

• sim7000.whitelist_remove_from_sms() -> int

  REMOVE <number>: 1 removed, 0 not on the list, -1 bad number, -2 fixed (admin or alert number)

• sim7000.whitelist_text() -> string

  The whitelist as SMS text, e.g. 'Allowed: 0776162283 (fixed), 0775438588'

Wiring

Specifications

Voltage

3.0-4.3V module supply (boards with a buck regulator take 5V+)

Current

up to ~2 A bursts when transmitting on GSM

Baud

9600 or 115200 depending on the board (check with AT; some are fixed with AT+IPR)

Networks

LTE Cat-M1, NB-IoT, GSM/GPRS 900/1800

Tips

• If the network has no LTE-M/NB-IoT, the modem can wait minutes in automatic mode; this driver forces GSM-only (AT+CNMP=13).
• Laptop USB power is not enough when it transmits; use a 2 A supply.
• A straight ~8 cm wire on the LTE antenna pad's centre pin works for testing; use a proper antenna in an enclosure.

Alternatives worth knowing:

• SIM800L: 2G-only, cheaper; some boards ship with IMEIs networks reject.