EXTECH 407760
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| File:Extech 407760.jpg | |
| Status | planned |
|---|---|
| Source code | tondaj-sl814 |
| Connectivity | tbd |
| Frequency range | tbd |
| Measurement range (A) | tbd |
| Resolution | tbd |
| Accuracy (94dB@1kHz) | tbd |
| Frequency weighting | tbd |
| Time weighting | tbd |
| Website | extech407760.cn |
The EXTECH 407760 is a sound level meter with USB connectivity.
See EXTECH 407760/Info for more details (such as lsusb -vvv output) about the device.
See EXTECH 407760/Beagle_dump for more details on protocol
Hardware
Device:
- Main CPU: TBD
- TBD: CEM DT-173
- TBD
- TBD
- TBD
- Battery: 3.6v 1/2 AA battery
it's hard to read the chip numbers There's two chips on this side of the board. Same markings on both They have the TI logo TI 062C 15K CV8J
USB cable:
- TBD
Photos
Device:
- Extech 407760.jpg
USB cable:
TBD
Protocol
The device has a usb connector. The device accepts bulk transfer commands on a usb bus.
Commands / replies
407760(EXTECH) Communication Protocol
Basic setup (64 byte in all, latter is 0)
0 1 2 3 4 5 6 7 8 9 10 11
LED STATUS Samprate Alarm HI Alarm Low y m d H M S Samp points
10
20
30
0
U8 U8 U8 U8 U8 U8 U8 U8 U8 U8 3U8
STATUS:
7 6 5 4 3
2
1 0
Auto：0
Manual：1 RT 1
STOR 0 1dBA
0dBC 1fast
0slow S:01
M:10
H:11
Samprate
0x01 represent 50ms
0x02 500ms
0x03 1s
0x04 2s
0x05 5s
0x06 10s
0x07 60s
Download the data
PC transmits the read-command 00,00,0D in read Mode.
If the first byte of reply is 0XFF , then it is STOR MODE
{STOR MODE
2
HI 1
M 0
LOW
Transmit the read-command 00,00,0f READ data
READ INFO
11 10 9 8 7 6 5 4 3
2
1
0
Alam
H
Alam
L
fs
unit
S
M
H
d m m
y Samprate
BLOCKBUF 512
Except the last time, It is sent BLOCKBUF real data
2
hi 1
lo 0
0x0f
Hi*256+lo is the times of reading data
//STOR MODE
}
If it not 0XFF, then it is REAL MODE
STATUS
7 6 5 4 3
2 1 0
Auto：0
Manual：1 RT/STOR check
1dBA
0dBC 11fast
0slow Samprate
SAMPRATE =0 this means EMS memory is empty
“serial parameters”
To connect to the device via USB, you will need to know the following for development..
VID : VID_10C4
PID : PID_0003
Baud rate : (9600)
Bit value : 8
Notes
TBD
Python script
Here's a quick Python script for getting the values out of the EXTECH 407760. A sigrok driver will follow soon.
#!/bin/python
import usb.core import sys dev = usb.core.find(idVendor=0x10c4, idProduct=0xea61)
- dev.baudrate=9600
dev.set_configuration() dev.reset()
bytes_written = dev.write(0x02, [0x00,0x00,0x0D], 0) print "_dbg bytes_written: ", bytes_written
for x in xrange(0,100):
print "_dbg attempting read for the %d time\n" % x
try:
data = dev.read(0x82, 1,0,1000)
if data:
print "Data found!\n"
sys.exit()
else:
print "Data not found!\n"
except:
pass
Example output:
TBD
Resources
TODO.