Ver 2.0
This article introduces the Realtek IoT wi-fi chip RTL8710BX basic performance and parameters, the Yang content couplet AFW121TI, for example, from module application description chip performance,
1 hardware
1.1 resources
A. basic peripheral modules:
B.W I - Fi initialization module is powered on maximum working current
Wi-fi module when the electricity is initialized, RF calibration and configuration register need in large current, need 500 ma, when connect the AP also need a certain amount of current support, advice power design maximum current more than 500 ma
C. under the same routing (AP), can support module equipment online number:
Commonly used routing number of connections experience value of 20-30, low-end router usually back 15, industrial level router quantity increase quantity to 300, the 13 2.4 G WIFI inside channel can be repeated use
D. mode of distribution network support and principle:
1, a key direct Fast - link 2, WeChat Airkiss 3, SoftAP hot distribution network
Air caught before the operation is simple, wifi module, the module through the phone app configuration (or other human machine interface) signal, extract the router information from a wireless network and configure the net, net compatibility and router encryption protocol associated with mobile phones and the current distribution network success rate of about 85% - 90%
SoftAP is wifi AP hotspot, cell phone (or other human machine interface) AP hotspot to search module, user name password writing network configuration in the router, distribution network success rate of nearly 100%
Recommend user APP end use of the combination, improve the product distribution network experience (jiujiu content provide APP distribution network interface, automatic switching source), usually have the AP + STA model to solve the problem of the distribution network
E. module set to AP hot model, support several connections?
The WLAN Driver support three Station connection, if there is demand can adjust the connection limit,
F. module support Soft - AP and Station mode coexist?
Support, wi-fi module after establishing Soft - AP, can at the same time as the Station mode into other AP (routing)
G. secondary welding:
Modules can accept secondary reflow soldering, reflow soldering the highest temperature at 260 degrees Celsius, pay attention to the welding temperature curve, the welding temperature area is best upper temperature is lower than the lower temperature, to avoid overheating of shielded enclosure,
H. connection distance:
Module can be divided into: on-board antenna and an external antenna (not including penetration with reinforced concrete floor)
On-board antenna open about 60 meters distance, external PCB antenna distance in 160 meters, open office environment nonbearing wall is usually connected to 25 meters (similar with apple mobile phone wifi distance)
I. lost package phenomenon:
Due to network speed faster than the rate of serial port, usually need to equipment, wifi module, server side three-way protocol packets adjustments, the wifi module is the default serial port receive buffer buff is 1.5 KB, each socket buffer for 2 KB, can meet the requirements of IOT data transmission,
1.2 power consumption
A, power mode summary and the parameter of the typical power consumption
1) peak power continuous TX 320 ma (distribution network power supreme)
2) module to keep connection when the average power consumption of 70 ma
3) keep link state routing module, Tickless sleep mode power average 5 ma
Module deep dormancy: power consumption is less than 10 ua (Wifi and ARM kernel dormancy, need external I/O wake up) (current is too small no legend)
Detailed parameters and power consumption can be the reference document "jiujiu power test coupon"
1.3 the Flash and RAM architecture
RTL8710BX internal Flash1MB (can support to 4 MB), SRAM256KB (Flash can execute code)
1.4 wi-fi module transmission power performance index
Note: the TX module rf performance mainly embodied in three parameters: the Power (Power), EVM entry (error vector magnitude), FreqErr (deviation)
1.5 wi-fi module receives the power performance index
2 software
2.1 initialization and connection time
A, wi-fi module initialization time: within 500 ms
B, a key quickly, Fast - link distribution network: 40 s keep polling channel process, distribution network time within 5 s success
C, AT + instructions written to distribution network information, for distribution network:
2 secondsD, the time of a TCP connection: the AT + instruction model within 2 s
E, Deep sleep mode clock details: Deep sleep mode using the wake up timer is an external low precision timer (1 KHZ), to set a maximum of 140 minutes, the measured set 140 minutes, about 10 minutes of the error,
F, deep sleep mode wake up system reboot time: the system reboot time=98 ~ 100 ms;
The AT + 2.2 instruction set functions
A, the wireless communication protocol: support IEEE802.11 b/g/n, n band connection by default
B, support the MAC address: MAC address access (AT + instructions)
C, scan all the information in the AP: single instruction operation
1. Support the SSID access (allows the maximum length of 128 bytes, support Chinese and special characters, single quotation marks except),
2. Support for MAC address of the AP,
3. Support for the safety of the AP mode,
4. Support for the frequency of the AP,
5. Support for AP signal (RSSI),
6. Support for the number of AP,
7. Support the scan results according to the signal strength when the AP by began sorting
8. Support your connection with the radio broadcast the SSID
9. Support IP set and get
D, data security:
Support of the security models and encryption algorithm, support for the following five kinds of safe mode: no security (password-less), WEP_OPEN (open certification), WEP_SHARED (Shared key authentication), WPA, connected,
E. dynamic IP access: use DHCP set static IP: not use DHCP
In the case of not using DHCP, AT + instruction set netmask address, network gateway address and DNS address;
F. reconnection mechanism: AP support automatic reconnection boot, abnormal disconnected automatic reconnection,
We've TTP server: support AT + instructions to open the HTTP server
H. system stability: in order to provide the stability of the system, operating environment to cope with more conflict, module integrates the watchdog mechanism, break line reconnection mechanism
I. burn application is not successful, check the Jtag wiring is correct, check whether LOG_Uart against
J. secondary development: provide Ameba C_SDK series as well as the design reference
K.W ifi module communication time
RTL8710BX series, due to the original ecological AT + instruction set contains the Log debugging information, Wifi module software debugging time is 200 ms returns a value, usually after removal of the Log output, about 40 ms feedback time
2.3 WIFI module application software q&a:
1. The firmware to restart automatically after complete AP automatic reconnection, reconnection rule:
Two cases:
A. restart when power disconnected, the module will read last time to save the information after successfully connected to the AP, AP information around search, if there is consistent, is to connect the AP, hot, if exist around the AP module is connected to the, if not the AP, the module will try launched eight reconnection mechanism (set), each time interval for 5 s (set)
B. module in the normal working time, when it connects the AP to disconnect the module in 18 s (late this time instead of within 5 s) after tell MCU has not connected, the AP will launch next eight reconnection mechanism, each time interval is 5 s
Hot WEP encryption type 2. According to the AP/WPA/connected/WAP ENT support covering how:
Support for the following five kinds of safe mode: no security (password-less), WEP_OPEN (open certification), WEP_SHARED (Shared key authentication), WPA, connected, for WPA/connected, to support for AES encryption algorithm and TKIP AP, ENT doesn't support the
3. SCAN out hot information, does not recognize Chinese characters and garbled?
Chinese characters of AP, module will take the Chinese characters in utf-8, if the router does not support utf-8, adjust coding need microcontroller drive end, otherwise there will be a random character or empty AP name,
4. How long can return the SCAN results [hot] contains less than?
2 seconds, without any AP, timeout is 2 seconds, can be installed
5. Scan to hot spot signal value (DBM) what is the minimum? Or scanning can return hot number up to a few?
Hot spot signal value application layer could not see, we are currently testing experience to see the range of 15 ~ - 100 DBM, scanning returns number of hot spots in the most support 64
6. Wifi working mode of the AP + STA work mode, from a performance comparison on a single AP/STA model what is the difference? The model of specific application scenario?
AP + STA model is a hot spot in module to establish the principle of the (AP), and then connect the other AP (routing), equivalent to the AP and the STA into effect two modes at the same time, compared to a single AP and STA model, it is the way that USES polling mode switching between the two, if use two mode to send and receive data at the same time, may be lost data
Customer usage: currently the AP + STA model, have the following usage:
A, LED control card industry, customer use this model as A standalone switch and networking flexible use
B, printer industry, customers in the network circumstances, opening its own hot phone state feedback information,
C, pos machine industry, equipment usually end with man-machine interface, can directly enter the router information, do not need to ap hot mode connection
7. AP SSID name maximum length support?
SSID maximum length of 32 bytes,
Article 8. Quickly send two the AT command would react? [the first response return value second to immediately send the AT command]?
Module receives the circular queue, the first response will not lose the second instruction not receive
9. After connected to the hot spots, placed for long, will be a router kick [] WIFI link?
Equipment will not be routing kicked off, because the module will have beacan issued
The network connection was the most support several handles? For a long time operation will not be active to release?
Eight can establish a Socket connection, more than 8 will establish unsuccessful
Long time no operation can't be released in active
11. The mechanism of the limitation of the TCP connection is what? [will maintain TCP connection constantly open] for a long time?
As the CLIENT side, the SERVER does not take the initiative to disconnect, will keep the connection, as a SERVER, will keep waiting for equipment access
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