Futek Qia128 Digital Low Power Controller With Spi And Uart User Guide

QIA128 Digital Low Power Controller with SPI and UART
User Guide

General Description

The QIA128 is a single-channel ultra-low-power digital controller with UART and SPI outputs.
Pin Configurations and Function Descriptions

Table 1.

QIA128 UART Configuration
Table 2. 

Pin Functionality

When the pin goes high, it means the device is in the process of A/D conversion. goes low as soon as the conversion is complete.
* Note: Since UART is asynchronous, the is provided to make the communication synchronous if required.
Period

The following table shows the period of the pin for all sampling rates.
Table 3.

“Stream” Mode

The Set System Stream State (SSSS) [with a payload of 1] command may be sent to activate the stream mode. The device will stop streaming as soon as the Set System Stream State command [with a payload of 0], or any other command is sent to QIA128.
*Note: There may be no response from the QIA128 if an incorrect command is sent.
UART Packet Structure
The packet structure and length for every command may vary due to their type (GET and SET) and functionalities; refer to the Command Set Table for further information.
System Behavior
Start-up and Self-Calibration Mode
When the system powers ON, it starts reading the data from EEPROM and goes to the internal calibration mode.
*Note: The first pulse could be used as an indicator for when the device is ready for communication.
Sampling Rate Change
When a sampling rate change is requested, it will take no more than 0.5 seconds (depending on the selected sampling rate) to see the change in the period.
Sampling Rates
Table 4.

Command-Set List

Table 6. 

QIA128 UART Communication Guide

*Note: The Payload bytes are located directly before the last byte of the packet which is the Checksum.

Payload Example
The following transaction is the response to the GDSN command (Get device serial number). This command has a payload of 4 bytes.
TX: 00 05 01 00 0D
RX: 00 09 01 00 00 01 E2 40 49
Hex to decimal: 0x0001E240 -> 123456

ADC Data Conversion

The following formula could be used to convert the raw ADC data:

Here are the variables:
ADCValue = the most recent analog-to-digital conversion value.
Off-set Value = the analog-to-digital conversion value stored during calibration that corresponds to the offset (zero physical loads).
Full-Scale Value = the analog-to-digital conversion value stored during calibration that corresponds to the full scale (maximum physical load).
Full-Scale Load = the numeric value stored during calibration for the maximum physical load.

ADC Data Conversion Examples (Direction 1, 2-point Calibration)

Calibration Data
Get profile analog-to-digital calibration value 0 (Direction 1) [GPADP]:
Hex to decimal: 0x81B320 -> 000,500,8
Get profile analog-to-digital calibration value 5 (Direction 1) [GPADP]:
Hex to decimal: 0xB71B00 -> 12,000,000
Get channel current reading (GCCR):
Hex to decimal: 0x989680 -> 10,0000,00
Calculation
OffsetValue = 8,500,000
FullScaleValue = 12,000,000
FullScaleLoad = 20g (Available on the calibration certificate)

Firmware Revision

Firmware Notes
New Features
• N/A
Changes
• N/A
Fixes
• Changed the hardware revision from “0” to “1”.

Sensor Solution Source
Load • Torque • Pressure • Multi-Axis • Calibration Instruments • Software
10 Thomas, Irvine, CA 92618 USA
Tel: (949) 465-0900
Fax: (949) 465-0905
www.futek.com