tracking devices/systems and mapping devices application。
 products list
model no. output
level back-up battery
type power
saving
ttl or rs-232 lithium
gm-85-t0x ttl y y
 specifications
snap start < 3 sec (at < 25 minutes off period)。
hot start 8 sec(typ)。
warm start 38 sec(typ)。
cold start 45 sec(typ)。
satellite reacquisition time accuracy 100 ms。
channels 12 satellites。
position accuracy 25m cep without sa。
receiver l1, c/a code。
protocol nmea-0183 v2.2, 4800, 8, n, 1, gga, gsa, gsv, mc.(vtg , gll, rms option) or sirf binary。
maximum altitude < 18,000 m (60,000 feet)。
maximum velocity < 515 m (700knote)。
max. update rate 1 hz。
rf connector mmcx。
interface rs232 or ttl level。
dimension 25.4mm(l)x25.4mm(w)xxxmm(h)。
weight xxg。
firmware upgrade flash memory for programming software available。
time mark output 1 pulse/sec, aligned with gps time +/ -0.1 usec。
operating temperature -40 to +85 。
storage temperature -45 to +100 。
operating humidity 5% to 95%, no condensing。
 electrical specifications：
less than 70ma (without antenna )。
 output terminal and definition ：
6 pin header (2.0mm pitch).
j1 connector pin definition:
pin pin name function description
1 vcc_5v +3.5~5.5vdc power input
2 txa serial data output port a
3 rxa serial data input port a
4 rxb serial data input port b
5 gnd power ground
6 timemark 1pps time mark output
1. vcc_5v: +3.3 ~ 5.5v dc voltage input.
2. dual communication channel ttl levels with user selectable baud rates (4800-default, 9600, 19200, 38400).
txa: main serial output. this output provides navigation data to user written software.
rxa: main receive channel. this input is used to receive software commands to the gm-85 from user written software.
rxb: auxiliary receive channel. this input is used to receive serial differential gps data.
3. timemark: this pin provides one-pulse-per-second output from the gm-85 board, which is synchronized to gps time. this is not available in trickle-power mode.
附电路图1：
电路2：
电路3：
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