sn74lvc1t45dbvr
sn74lvc1t45dbvr是什么总线收发芯片呀
求解
它不是什么总线收发芯片，而是一个用于总线或是信号线电平转换的芯片。
具体的功能，可以在TI的官网上面查找datasheet。
谢谢
双电源电平转换器件，可以用与多种总线接口，解决电平不匹配问题
您好，用cc3200开发板uart输出wifi信号强度，为啥用串口助手能看到16进制的强度值，但是用示波器放在 sn74lvc1t45dbvr4引脚上检测不到电平变化，一直都是3.3V呢？
能不能把sn74lvc1t45的相关部分原理图附上来
CC3200的原理图和我用示波器检测时的照片都附上了，谢谢啦
您可以电话联系我吗？很着急的问题，还是学生，请赐教呀。13520001544
是不是因为
static long WlanScan(void *pvParameters)
{
long lRetVal = -1;
unsigned short ucIndex;
unsigned char ucpolicyOpt;
union
{
unsigned char ucPolicy[4];
unsigned int uiPolicyLen;
}policyVal;
InitializeAppVariables();
//
// Following function configure the device to default state by cleaning
// the persistent settings stored in NVMEM (viz. connection profiles &
// policies, power policy etc)
//
// Applications may choose to skip this step if the developer is sure
// that the device is in its default state at start of applicaton
//
// Note that all profiles and persistent settings that were done on the
// device will be lost
//
lRetVal = ConfigureSimpleLinkToDefaultState();
if(lRetVal < 0)
{
if (DEVICE_NOT_IN_STATION_MODE == lRetVal)
{
UART_PRINT("Failed to configure the device in its default state\n\r");
}
return lRetVal;
}
//UART_PRINT("Device is configured in default state \n\r");
//
// Assumption is that the device is configured in station mode already
// and it is in its default state
//
lRetVal = sl_Start(0, 0, 0);
if (lRetVal < 0 || ROLE_STA != lRetVal)
{
UART_PRINT("Failed to start the device \n\r");
return lRetVal;
}
//UART_PRINT("Device started as STATION \n\r");
//
// make sure the connection policy is not set (so no scan is run in the
// background)
//
ucpolicyOpt = SL_CONNECTION_POLICY(0, 0, 0, 0,0);
lRetVal = sl_WlanPolicySet(SL_POLICY_CONNECTION , ucpolicyOpt, NULL, 0);
if(lRetVal != 0)
{
GPIO_IF_LedOn(MCU_EXECUTE_FAIL_IND);
UART_PRINT("Unable to clear the Connection Policy\n\r");
return lRetVal;
}
//
// enable scan
//
ucpolicyOpt = SL_SCAN_POLICY(1);
//
// set scan cycle to 10 seconds
//
policyVal.uiPolicyLen = 10;
//
// set scan policy - this starts the scan
//
lRetVal = sl_WlanPolicySet(SL_POLICY_SCAN , ucpolicyOpt,
(unsigned char*)(policyVal.ucPolicy), sizeof(policyVal));
if(lRetVal!=0)
{
GPIO_IF_LedOn(MCU_EXECUTE_FAIL_IND);
UART_PRINT("Unable to set the Scan Policy\n\r");
return lRetVal;
}
MAP_UtilsDelay(8000000);
//
// get scan results - all 20 entries in one transaction
//
ucIndex = 0;
//
// retVal indicates the valid number of entries
// The scan results are occupied in netEntries[]
//
lRetVal = sl_WlanGetNetworkList(ucIndex, (unsigned char)WLAN_SCAN_COUNT,
&netEntries[ucIndex]);
if(lRetVal==0)
{
GPIO_IF_LedOn(MCU_EXECUTE_FAIL_IND);
UART_PRINT("Unable to retreive the network list\n\r");
return lRetVal;
}
/* put a break point here and check netEntries[] value for scan ssid list */
//
// get scan results - 4 transactions of 5 entries
//
ucIndex = 0;
memset(netEntries, 0, sizeof(netEntries));
do
{
lRetVal = sl_WlanGetNetworkList(ucIndex,
(unsigned char)WLAN_SCAN_COUNT/4,
&netEntries[ucIndex]);
ucIndex += lRetVal;
}
while ((lRetVal == WLAN_SCAN_COUNT/4) && (ucIndex < WLAN_SCAN_COUNT));
/* put a break point here and check netEntries[] value for scan ssid list */
//
// disable scan
//
ucpolicyOpt = SL_SCAN_POLICY(0);
lRetVal = sl_WlanPolicySet(SL_POLICY_SCAN , ucpolicyOpt, NULL, 0);
if(lRetVal != 0)
{
GPIO_IF_LedOn(MCU_EXECUTE_FAIL_IND);
UART_PRINT("Unable to Clear the Scan Policy\n\r");
return lRetVal;
}
//UART_PRINT("SUCCESS\n\r");
return SUCCESS;
}
这个扫描WIFI信号的函数速度太慢了，11秒扫描一次，所以示波器显示不出来？怎么提高这个的扫描速度呢？
求解呀大神
原理图部分没有问题，你的意思是串口输出到调试助手上有信号，但是用示波器看不到信号？串口连电脑时你接的引脚和你用示波器测试的引脚都是哪些引脚啊？或者你使用USB板子上接口看的串口数据？
就是你说的那样，示波器上没有显示数据，但用USB连电脑，在串口助手上能接受到数据，是因为传输速度太慢吧？还有我买的就是ti的cc3200开发板呀，你用过吗？电话联系可以吗？太慢了这样，也说不太清楚
我没用过这个板子，我是负责接口相关的，对无线产品不太了解。但是你说的这种情况不太可能啊，输出有数据，示波器怎么会看不到数据呢？这跟速度没有关系啊，串口有数据，说明SN74LVC1T45向串口转USB的那片IC传了数据，说明引脚上肯定是有电平波动的数据的啊，你确定示波器没有问题的吗