m5stack ATGM336H ATOMIC GPS Base v2.0

AI context

Dense context for pasting into a model prompt — addresses, pinout, voltages, tolerances and the vendor's reference circuit.

PART: M5Stack Atomic GPS Base v2.0, SKU A134-V2, a 48.0 x 24.0 x 17.5 mm expansion base that carries an ATGM336H-6N-74 GNSS module (the vendor's specification line reads 'ATGM336H-6N-74 module @AT6668', so the module is the ATGM336H-6N-74 and the receiver die inside it is the AT6668), a ceramic patch antenna and an AT2659 low-noise amplifier, plus a TPAP7343D-33FS4 3.3 V LDO. It is a positioning receiver for the Atom series, not a general-purpose board; it outputs NMEA0183 4.1 sentences over a UART at 115200 baud, 8N1.
ADDRESSES: none. The board carries no I2C device and no addressable part, so there is no bus address to configure.
PINOUT: M5Stack numbers the base's Atom interface 1-9 in its own pin table, with the odd pins in one column and the even pins in the other (pin 1 has no partner in the even column): 1 = NC, 2 = NC, 3 = UART_TX, 4 = NC, 5 = UART_RX, 6 = 5V, 7 = RST, 8 = GND, 9 = NC. UART_TX on pad 3 and UART_RX on pad 5 reach the module through 22 ohm 1% series resistors (R1, R2) in the vendor's schematic; RST on pad 7 pulls the module's nRESET.
MODULE PINOUT: the ATGM336H-6N-74 footprint in the same schematic numbers 1 = GND, 2 = TXD0, 3 = RXD0, 4 = 1PPS, 5 = ON/OFF, 6 = VBAT, 7 = Reserved, 8 = VCC, 9 = nRESET, 10 = GND, 11 = RF_IN, 12 = GND, 13 = Reserved, 14 = VCC_RF, 15 = Reserved, 16 = RXD1, 17 = TXD1, 18 = Reserved. The module's 1PPS output is not brought out to the Atom interface, so a timing application has to reach the module pad itself.
SUPPLY: 5 V from the host Atom on pad 6, regulated to 3.3 V for the module by a TPAP7343D-33FS4 LDO. Measured on the vendor's page: standby 5.01 V at 4.95 mA, operating 5.02 V at 35.07 mA. Decoupling in the schematic: C6 10 uF and C5 0.1 uF on the 5 V input, C4 10 uF and C3 0.1 uF on the 3V3 rail, with LB1 a 100 ohm at 100 MHz ferrite bead between the rails. R3 1 k in series with LED1 is the board's status indicator.
LOGIC: 3.3 V UART both ends - the module runs from 3.3 V and the Atom's UART is 3.3 V, and the two are joined only by the 22 ohm series resistors, which are for edge-rate control, not level shifting. Do not feed a 5 V UART into pad 3 or pad 5.
RECEIVER FACTS: 50 channels, satellites received are BDS B1/B1C, GPS and QZSS L1, GALILEO E1 and GLONASS L1, either single-system or in any combination; positioning accuracy <1.5 m CEP50; output 1 Hz with 10 Hz maximum update rate; cold start 23 s, hot start 1 s, reacquisition 1 s; tracking sensitivity -167 dBm, reacquisition -160 dBm, cold start -148 dBm, hot start -156 dBm.
TRAPS: (1) The vendor contradicts itself on the receiver: the product description says the base 'integrates a high-performance AT6668 chip', the specifications table says 'ATGM336H-6N-74 module @AT6668', and the product-comparison table lists the module model as 'AT6668' while the product title says ATGM336H. All three strings are recorded here unresolved; the schematic's own part is ATGM336H-6N-74. (2) The description calls the LNA a MAX2659 while the data-sheet link on the same page serves an AT2659 document - again recorded, not resolved. (3) Six of the nine interface pins are NC, so the base occupies the Atom's socket without passing anything else through. (4) The base has no microSD slot; the older Atomic GPS Base had one.